RT state managment and rectangle support

dotnet/AipsRT/Model/Whiteboard/Structs/Position.cs

@@ -0,0 +1,13 @@
+namespace AipsRT.Model.Whiteboard.Structs;
+
+public struct Position
+{
+    public int X { get; set; }
+    public int Y { get; set; }
+
+    public Position(int x, int y)
+    {
+        X = x;
+        Y = y;
+    }
+}