Validierungslogik optimiert und Debug-Logs erweitert

Die Validierungslogik wurde flexibler gestaltet, indem die Bedingung
`pRegularComplete` eingeführt wurde. Wenn diese `False` ist, werden
bestimmte Validierungen übersprungen, und Debug-Nachrichten dokumentieren
das Verhalten.

- SQL-Löschoperationen erweitert, um zusätzliche Tabellen zu berücksichtigen.
- Prüfung auf `DBNull`-Werte bei `oValueFromSource` hinzugefügt.
- Validierungen für `LookupControl3`, Textboxen, ComboBoxen,
  DateTimePicker, CheckBoxen und DataGridViews angepasst.
- Debug-Logs in allen Validierungsfällen verbessert, um die Nachvollziehbarkeit
  zu erhöhen und unnötige Fehlermeldungen zu reduzieren.

app/TaskFlow/frmValidator.vb

@@ -813,7 +813,8 @@ Public Class frmValidator
 
             Try
                 Dim oSQL As String
-                oSQL = $"DELETE FROM TBPM_DOCWALKOVER WHERE UserID = {USER_ID};"
+                oSQL = $"DELETE FROM TBPM_DOCWALKOVER WHERE UserID = {USER_ID};" & vbCrLf &
+                    $"DELETE FROM TBPM_VALIDATION_PROFILE_GROUP_USER WHERE UserID = {USER_ID};"
                 DatabaseFallback.ExecuteNonQueryECM(oSQL)
             Catch ex As Exception
                 MyValidationLogger.Error(ex)
@@ -5304,8 +5305,8 @@ Public Class frmValidator
                                         oValueFromSource = GetVariableValuefromSource(oSourceIndexName, oIDBTyp, oIDBOverride)
                                     End If
 
-                                    If oValueFromSource Is Nothing Then
+                                    If oValueFromSource Is Nothing Or IsDBNull(oValueFromSource) Then
-                                        MyValidationLogger.Debug($"oMyComboBox {oMyCombobox.Name} - Indexvalue from index {oSourceIndexName}: Nothing")
+                                        MyValidationLogger.Debug($"oMyComboBox {oMyCombobox.Name} - Indexvalue from index {oSourceIndexName} is Nothing or DBNull")
                                         If oDefaultValue = String.Empty Then
                                             MyValidationLogger.Debug($"oMyComboBox {oMyCombobox.Name}-defaultValue wurde nicht gefunden")
                                             oMyCombobox.SelectedIndex = -1
@@ -7084,13 +7085,18 @@ Public Class frmValidator
                     Case oControl.GetType = GetType(LookupControl3)
                         Try
                             Dim lookup As LookupControl3 = oControl
-                            If lookup.Properties.SelectedValues.Count = 0 And oIsRequired = True And pRegularComplete Then
+                            If lookup.Properties.SelectedValues.Count = 0 And oIsRequired = True Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] LookupGrid '{oControl.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = $"Pflichtfeld: Keine Auswahl getroffen in LookupGrid '{oControl.Name}'"
                                     MyValidationLogger.Warn($"⚠️ {oErrMsgMissingInput}")
                                     oControl.BackColor = Color.Red
                                     OpenfrmError(oErrMsgMissingInput)
                                     Exit For
+                                End If
                             Else
                                 If lookup.Properties.MultiSelect = True Then
                                     Dim oLookupRows As Integer = lookup.Properties.SelectedValues.Count
@@ -7142,14 +7148,20 @@ Public Class frmValidator
                                         End If
                                     End If
                                 Else
+
                                     ' Single-Select Lookup
                                     oMyInput = lookup.Properties.SelectedValues.FirstOrDefault()
-                                    If IsNothing(oMyInput) And oIsRequired = True And pRegularComplete Then
+                                    If IsNothing(oMyInput) And oIsRequired = True Then
+                                        If pRegularComplete = False Then
+                                            MyValidationLogger.Debug($"[CHECK_UPDATE] LookupGrid(SingleSelect) '{lookup.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                            Continue For
+                                        Else
                                             oMissing = True
                                             oErrMsgMissingInput = $"Could not get FirstOrDefault-Value of LookUpGrid! - LookUPGridName: {lookup.Name}"
                                             MyValidationLogger.Warn(oErrMsgMissingInput)
                                             OpenfrmError(oErrMsgMissingInput)
                                             Exit For
+                                        End If
                                     ElseIf IsNothing(oMyInput) And oIsRequired = False Then
                                         For Each ochangedLookub In listChangedLookup
                                             If lookup.Name = ochangedLookub Then
@@ -7280,13 +7292,18 @@ Public Class frmValidator
                                 Exit For
                             End If
 
-                            If Check_Missing_Control_Value(oControl, "txt") = True And oIsRequired = True And pRegularComplete Then
+                            If Check_Missing_Control_Value(oControl, "txt") = True And oIsRequired = True Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] TextEdit '{oControl.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = oWrongInputMessage & " textbox '" & oControl.Name & "'"
                                     MyValidationLogger.Warn(oErrMsgMissingInput)
                                     oControl.BackColor = Color.Red
                                     frmError.ShowDialog()
                                     Exit For
+                                End If
                             Else
                                 MyValidationLogger.Debug("Reading current value from Textbox")
                                 Dim oTextEdit As BaseEdit = DirectCast(oControl, BaseEdit)
@@ -7410,7 +7427,11 @@ Public Class frmValidator
                         Try
                             MyValidationLogger.Debug($"Working on Combobox...")
                             Dim cmb As Windows.Forms.ComboBox = oControl
-                            If cmb.SelectedIndex = -1 And oIsRequired = True And pRegularComplete Then
+                            If cmb.SelectedIndex = -1 And oIsRequired = True Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] ComboBox '{cmb.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = "Please Choose an entry out of ComboBox '" & cmb.Name & "'"
                                     MyValidationLogger.Warn(oErrMsgMissingInput)
@@ -7420,6 +7441,7 @@ Public Class frmValidator
                                     End If
                                     OpenfrmError(oErrMsgMissingInput)
                                     Exit For
+                                End If
                             Else
                                 oMyInput = cmb.Text
                                 MyValidationLogger.Debug($"inputvalue Combobox: {cmb.Text}")
@@ -7545,7 +7567,11 @@ Public Class frmValidator
                     Case oControl.GetType = GetType(DateTimePicker)
                         Try
                             Dim dtp As DateTimePicker = oControl
-                            If oIsRequired = True And dtp.Value.ToString = String.Empty And pRegularComplete Then
+                            If oIsRequired = True And dtp.Value.ToString = String.Empty Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] DateTimePicker '{dtp.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = "Please Choose DateValue for field'" & dtp.Name & "'"
                                     MyValidationLogger.Warn(oErrMsgMissingInput)
@@ -7555,6 +7581,7 @@ Public Class frmValidator
                                     End If
                                     OpenfrmError(oErrMsgMissingInput)
                                     Exit For
+                                End If
                             ElseIf dtp.Value.ToString <> "01.01.0001 00:00:00" Then
                                 oMyInput = CDate(dtp.Value)
                                 Dim oObjectValue
@@ -7641,7 +7668,11 @@ Public Class frmValidator
                             Dim chk As CheckBox = oControl
                             oMyInput = chk.Checked.ToString
 
-                            If chk.CheckState = CheckState.Indeterminate And oIsRequired = True And pRegularComplete Then
+                            If chk.CheckState = CheckState.Indeterminate And oIsRequired = True Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] CheckBox '{chk.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = "Please set Checkbox value for field '" & chk.Name & "'"
                                     MyValidationLogger.Warn(oErrMsgMissingInput)
@@ -7652,6 +7683,7 @@ Public Class frmValidator
                                     OpenfrmError(oErrMsgMissingInput)
                                     Exit For
                                 End If
+                            End If
 
                             Dim WertWD As String
                             Dim oBoolValue As Boolean
@@ -7759,7 +7791,11 @@ Public Class frmValidator
                                     Zeilen += 1
                                 End If
                             Next
-                            If oIsRequired = True And Zeilen = 0 And pRegularComplete Then
+                            If oIsRequired = True And Zeilen = 0 Then
+                                If pRegularComplete = False Then
+                                    MyValidationLogger.Debug($"[CHECK_UPDATE] DataGridView '{dgv.Name}' is required but has no selection. Skipping due to pRegularComplete=False.")
+                                    Continue For
+                                Else
                                     oMissing = True
                                     oErrMsgMissingInput = "Fehlende Eingabe in Vektorfeld '" & dgv.Name & "'"
                                     MyValidationLogger.Warn(oErrMsgMissingInput)
@@ -7769,6 +7805,7 @@ Public Class frmValidator
                                     End If
                                     OpenfrmError(oErrMsgMissingInput)
                                     Exit For
+                                End If
                             ElseIf Zeilen > 0 Then
                                 Dim ZeilenGrid As Integer = 0
                                 Dim myVektorArr As String()