Add Quit option to 'Python' menu on the menubar when running a Thonny sketch or regular Sketch

[hx2A]

Does py5 have any control over the 'Python' menu on the menubar when running a Thonny sketch?

As soon as the 'Run' button is hit Thonny's menu is replaced by the 'Python' menu, but there are no menuItems as shown below in a normal app menu such as in the Thonny app:

There should at a minimum be a 'Quit cmd-Q' menuItem and I would like to see this added if py5 creates this menu initially. If Python or Thonny is creating the menu then it would appear to be beyond our control. Thanks.

Originally posted by @vsquared in #627

[hx2A]

Solution / fix is to add something like this to keyPressed(KeyEvent event):

  public void keyPressed(KeyEvent event) {
    if (platform == MACOS && event.isMetaDown() && (event.getKey() == 'q' || event.getKey() == 'Q')) {
        exit();
    }
...

This won't work for JavaFx though, get the IllegalStateException error. Must fix #668 first, then this can be fixed.