At the moment we trigger the edges even when the active window is full
screen which is unfortunate when running certain games, for example when
you're attacking the village at the north-east in Age of Empires and you
have the Overview effect on.

This changes the default to inhibit them (like we used to just do for
sides but not corners for some reason) and adds a checkbox to restore
them even in that case.

BUG: 441464