Framework changed to WPF

Only the basic window frame is implemented.
Adjusted the structure of resource files.

Source/GrasscutterTools/Models/GameItem.cs

@@ -0,0 +1,16 @@
+namespace GrasscutterTools.Models
+{
+    public class GameItem
+    {
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+
+        public string Category { get; set; }
+
+        public override string ToString()
+        {
+            return $"{Id} : {Name}";
+        }
+    }
+}