Make Clipboard argument in Widget trait mutable

native/src/widget/column.rs

@@ -141,9 +141,9 @@ where
         event: Event,
         layout: Layout<'_>,
         cursor_position: Point,
-        messages: &mut Vec<Message>,
         renderer: &Renderer,
-        clipboard: Option<&dyn Clipboard>,
+        clipboard: &mut dyn Clipboard,
+        messages: &mut Vec<Message>,
     ) -> event::Status {
         self.children
             .iter_mut()
@@ -153,9 +153,9 @@ where
                     event.clone(),
                     layout,
                     cursor_position,
-                    messages,
                     renderer,
                     clipboard,
+                    messages,
                 )
             })
             .fold(event::Status::Ignored, event::Status::merge)