Mouse support?

[LunaMoo]

After #12173 and #12176 get's merged, mouse will not keep tiny values when using small axis to button threshold and as such include only minimal threshold to react on even tiny mouse move / without delay, it'll also avoid using mapped PSP keys in UI as this could be problematic especially when mapping it to cross or circle.

If someone wants to test mouse movement in a visible way after those patches get merged, I would recommend mapping mouse to left analog and d-pad and using touch screen controls, that's also a good way to find out what sensitivity and smoothing settings you might like for the mouse as it shows exactly how mouse mapped to analog/buttons behaves and gives better idea why I even added those settings in the first place.

Edit: Both of my PR were merged improving mouse control, so I'd recommend using version v1.8.0-424-geeb349121 or above to play with a mouse.