Refactor EnvelopeEditorController for type consistency

- Updated constructor to cast receivers to EnvelopeReceiver.
- Changed ResendReceiverInvitation parameter from Receiver to ReceiverVM.
- Modified ValidateEnvelopeForSending to use EnvelopeReceiver and correct ID for validation.

EnvelopeGenerator.Form/Controllers/EnvelopeEditorController.vb

@@ -30,7 +30,7 @@ Public Class EnvelopeEditorController
 
         Envelope = pEnvelope
         Envelope.Documents = DocumentModel.List(pEnvelope.Id).ToList()
-        Envelope.Receivers = ReceiverModel.ListEnvelopeReceivers(pEnvelope.Id).ToList()
+        Envelope.Receivers = ReceiverModel.ListEnvelopeReceivers(pEnvelope.Id).Cast(Of EnvelopeReceiver)().ToList()
 
         Thumbnail = New Thumbnail(pState.LogConfig)
         ActionService = New ActionService(pState, Nothing)
@@ -43,7 +43,7 @@ Public Class EnvelopeEditorController
     Public Function DocumentRotationChanged() As Boolean
         Return ActionService.SetStatusDocumentRotationChanged(Envelope)
     End Function
-    Public Function ResendReceiverInvitation(pEnvelope As Envelope, pReceiver As Receiver) As Boolean
+    Public Function ResendReceiverInvitation(pEnvelope As Envelope, pReceiver As ReceiverVM) As Boolean
         Return ActionService.ResendReceiver(pEnvelope, pReceiver)
     End Function
 
@@ -56,8 +56,8 @@ Public Class EnvelopeEditorController
 
         If ElementModel.OneElementPerReceiverExist(Envelope.Id) = False Then
 
-            For Each receiverItem As Receiver In Envelope.Receivers
-                If ElementModel.ElementsExist(Envelope.Id, receiverItem.Id) = False Then
+            For Each receiverItem As EnvelopeReceiver In Envelope.Receivers
+                If ElementModel.ElementsExist(Envelope.Id, receiverItem.Envelope.Id) = False Then
                     oEnvelopeErrors.Add(String.Format(Resources.Envelope.Missing_Elements_for_Receiver, receiverItem.Name))
                 End If
             Next