One failure case: When there is a fullscreen window directly to the right of a game, for example, in a multimonitor setup, then the cursor will bug out in between the monitors. sometimes it will get constrained to the border, but just outside the window (which is what this PR fixes, so it's unusual) and sometimes the cursor will just ignore the constraint entirely. However this is only in the one case.
The window properly constrains the mouse now
I do still notice a bug with moving the mouse in games, if you don't move the mouse fast enough, some games will not register the mouse movement. This doesn't happen in KDE so I know it's related somehow
This is a first version of my test to properly constrain cursors. This is mostly working in the buggy applications I had before, but I feel that the cursor needs to actually move around, instead of being locked to the center of the window.
This may cause problems when locking to the edge, but yeah.
