Fix disappearing software cursor in overview and zoom effect
The overview and the zoom effect repaint the whole screen every frame. But the problem is that there are cases when there's nothing to repaint. I'm not quite sure why it happens. Maybe overview and other effects should honor the repaint region, but on the other hand, they don't need to because of the fullscreen effect api promises.
This change forces overview and zoom effect to use "generic paint" code path in the workspace scene to force infiniteRegion() repaint regions.
Edited by Vlad Zahorodnii