macOS: Window doesn't re-open if the window is closed

[JeffersonBledsoe]

On macOS you can close a window without the app quitting. This is useful as the window is gone from the window manager but the music will continue to play if you're using the built-in squeezelite. However, macOS typically allows you to re-click the application use the Window menu to re-open the window. This doesn't work with the MA desktop app and the only way to see the application again is to quit the app and re-open it