[bug] First click on a MenuItem at the root of a Menu behaves the same as a Submenu

[sharky98]

I created the issue in Tauri tauri-apps/tauri#12649, but after a quick test, I think the behavior come from this library. I used the tao.rs example, simply adding a MenuItem at the root.

Doing so, the event is not trigerred when clicking on Fake Close, only on the second click (as if the first click opened the absent submenu and the second click triger the event)

    let file_m = Submenu::new("&File", true);
    let edit_m = Submenu::new("&Edit", true);
    let window_m = Submenu::new("&Window", true);
+    let close_m = MenuItem::new("Fake Close", true, None);

-     menu_bar.append_items(&[&file_m, &edit_m, &window_m]);
+     menu_bar.append_items(&[&file_m, &edit_m, &window_m, &close_m]);

    let custom_i_1 = MenuItem::with_id(
        "custom-i-1",
        "C&ustom 1",
        true,
        Some(Accelerator::new(Some(Modifiers::ALT), Code::KeyC)),
    );