Allow maximize/fullscreen of the DeskPad window

[glenmurphy]

MacOS' Spaces is limited by forcing all spaces to the same resolution, so you can't have an easy-to-read consumption spaces and a high-res programming space. DeskPad on its own dedicated space almost solves this, but would be made better by adding fullscreen support to avoid the double-menubar problem; it would also remove the need for manually creating a space for DeskPad ahead of time.

[aptonline]

In a similar vain, enabling the standard Mac OS window menu would give the ability to use window tiling functionality and keyboard shortcuts within Sequoia.