added groupId to groupDragged event

lib/timeline/component/ItemSet.js

@@ -1598,7 +1598,7 @@ ItemSet.prototype._onGroupDragEnd = function (event) {
 
           }
           
-          me.body.emitter.emit('groupDragged');
+          me.body.emitter.emit('groupDragged', { groupId: this.groupTouchParams.group.groupId });
         });
 	}
 }