Dev wpf (#15)

Convert Namespaces designer to WPF/MVVM
Create C# custom action to detect VS2019 and not require WiX 3.14 to build IsWiX installer

Application/Designers/NamespacesDesigner/Models/NamespaceModel.cs

@@ -0,0 +1,20 @@
+using FireworksFramework.Types;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NamespacesDesigner.Models
+{
+    public class NamespaceModel : ObservableObject
+    {
+        string _prefix;
+        string _uri;
+        bool _selected;
+        public bool Selected { get { return _selected; } set { _selected = value; RaisePropertyChangedEvent("Selected"); } }
+        public string Prefix { get { return _prefix; } set { _prefix = value; RaisePropertyChangedEvent("Prefix"); } }
+        public string Uri { get { return _uri; } set { _uri = value; RaisePropertyChangedEvent("Uri"); } }
+
+    }
+}