Ensure ObservableCollection<> assembly and namespace are included in .Designer.cs fiiles

Author: tznind

src/FromCode/CodeToView.cs

@@ -1,4 +1,5 @@
 using System.Collections;
+using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.Reflection;
 using System.Text.RegularExpressions;
@@ -160,6 +161,7 @@ public Assembly CompileAssembly()
             MetadataReference.CreateFromFile(typeof(System.Linq.Enumerable).Assembly.Location),
             MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
             MetadataReference.CreateFromFile(typeof(MarshalByValueComponent).Assembly.Location),
+            MetadataReference.CreateFromFile(typeof(ObservableCollection<string>).Assembly.Location),
 
             // New assemblies required by Terminal.Gui version 2
             MetadataReference.CreateFromFile(typeof(Size).Assembly.Location),

src/ToCode/ViewToCode.cs

@@ -127,6 +127,7 @@ public void GenerateDesignerCs(Design rootDesign, Type viewType)
         ns.Imports.Add(new CodeNamespaceImport("Terminal.Gui"));
         ns.Imports.Add(new CodeNamespaceImport("System.Collections"));
         ns.Imports.Add(new CodeNamespaceImport("System.Collections.Generic"));
+        ns.Imports.Add(new CodeNamespaceImport("System.Collections.ObjectModel"));
         ns.Imports.Add(new CodeNamespaceImport("System.Drawing"));
 
         this.AddCustomHeaderForDesignerCsFile(ns);