Keyboard navigation with arrow keys is broken

[alzwded]

Make keyboard navigation predictable while taking monitor geometry into account.

E.g.: if two monitors are configured side-by-side, pressing left on the right one should jump on the left one if it's on a border. It should also wrap around.

The behaviour should be based on hitboxes. I.e. starting from one slot and moving up, a target point should be drawn in the logical "up" section, and if something's hit, move to that slot. If there is no slot, wrap around. This should be predictable and should work for most users.