feat: add two attached properties to mark an custom element triggering drag move or close.

src/Ursa/Controls/Dialog/Options/OverlayDialogOptions.cs

@@ -28,4 +28,5 @@ public class OverlayDialogOptions
     public bool IsCloseButtonVisible { get; set; } = true;
     
     public bool CanLightDismiss { get; set; }
+    public bool CanDragMove { get; set; } = true;
 }