fix menu removeAll should work on a copy of the menu items list.

Author: vegegoku

domino-ui/src/main/java/org/dominokit/domino/ui/menu/Menu.java

@@ -565,7 +565,7 @@ public Menu<V> removeItemAt(int index) {
    * @return The current Menu instance.
    */
   public Menu<V> removeAll() {
-    menuItems.forEach(BaseDominoElement::remove);
+    new ArrayList<>(menuItems).forEach(this::removeItem);
     menuItems.clear();
     closeCurrentOpen();
     currentOpen = null;