desktopGrid: Use the maximized state on startup
During startup (including monitor hotplugging), mutter can get stuck in an infinite loop trying to adhere to its window constraints logic for our fixed-size window, if there are two monitors of different scales in a Wayland session.
When this happens, we don't have hide_from_window_list set because
the infinite loop starts before we can even set it. So we need a
solution that works for regular window types.
To solve this we make the window maximized by default. This stops mutter's constraints logic from wanting to automatically move the window between monitors.
Yes we should fix mutter, but that will take much longer to get right.