use DragEvent not MouseEvent for drag events (#3137)

* use DragEvent not MouseEvent for drag events

* Simplify drag events and remove WebDragData struct

* use DragEvent not MouseEvent for drag events

* re-add the web_sys event reference for drag + mouse data

* remove now vestigial impls for MouseEvent

---------

Co-authored-by: Matt Hunzinger <matthunz2@gmail.com>

packages/web/src/events/composition.rs

@@ -9,7 +9,7 @@ impl HasCompositionData for Synthetic<CompositionEvent> {
     }
 
     fn as_any(&self) -> &dyn std::any::Any {
-        self
+        &self.event
     }
 }