Fix: Add "Read and confirmed" label for RaC envelopes

Updated the Signature Certificate report to display the correct
label "Read and confirmed" for "Read and Sign" envelopes.

- Added `DocumentSignedRaC` resource key to `Model.resx` and
  `Model.en.resx` with localized values ("Gelesen und bestätigt"
  and "Read and confirmed").
- Updated `ReportItem.vb` to include conditional logic in
  `ItemStatusTranslated` for "Read and Sign" envelopes.
- Added strongly-typed property for `DocumentSignedRaC` in
  `Model.Designer.cs`.
- Updated `fix-report-label-read-and-confirmed.md` documentation
  to reflect changes, including testing steps and task completion.

These changes ensure accurate status labels in the report for
different envelope types.

EnvelopeGenerator.Domain/Resources/Model.Designer.cs

@@ -213,6 +213,15 @@ namespace My.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Gelesen und bestätigt.
+        /// </summary>
+        public static string DocumentSignedRaC {
+            get {
+                return ResourceManager.GetString("DocumentSignedRaC", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Entwurf.
         /// </summary>