chore: separated System.Windows.Interactivity code

src/Shared/System.Windows.Interactivity/PreviewInvokeEventArgs.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace HandyControl.Interactivity;
+
+public class PreviewInvokeEventArgs : EventArgs
+{
+    public bool Cancelling { get; set; }
+}