script: Expose NodeTraits::owner_global / Window::as_global_scope (#34843)

Expose two new helpers and start using them as much as possible.

- `NodeTraits::owner_global`: which gets the `GlobalScope` that currenty
 owns a `Node`. This may be different than `.global()` in the case that
 the `Node` was adopted by a different `Document`.
- `Window::as_global_scope`: A helper to avoid having to cast so much
  when treating a `Window` like a `GlobalScope`.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/script/dom/textcontrol.rs

@@ -301,7 +301,7 @@ impl<'a, E: TextControlElement> TextControlSelection<'a, E> {
         // Step 6
         if textinput.selection_state() != original_selection_state {
             self.element
-                .owner_window()
+                .owner_global()
                 .task_manager()
                 .user_interaction_task_source()
                 .queue_event(