We want a native menu bar for the top-level application window but we also want to create menu bars in panes and subwindows that don't replace the application menu bar.

Since we want native menus and non-native menus, the application attribute to disable native menus doesn't help us.

Please add a property (e.g. `native: false`) to the `MenuBar` item to prevent the item from creating a native menu bar on macOS.

To work around this we're going to have to create our own duplicate MenuBar implementation which will be a pain.