This was just not implemented end to end. There are still two notable
issues, one that I can live with, one I need to narrow down eventually:
1. Rebinding confirm buttons with trigger (ie. X) behaviour is not 100%
as it should be. I fixed it enough that I can live with it but it's
still not proper. The difficulty is that unlike a button it will
re-trigger the pressed state on the journey back to neutral (aka
unpressed).
2. If you change the bind for the confirm button, then reset your
bindings, the next confirm input is eaten. This is unrelated to these
changes but I briefly looked into it and was unable to find the root
cause.
The current event-based approach is very difficult to get right, and it
depends on no events ever being missed. This changes the keyboard/mouse
handling code to a polling-based approach.
Other fixes:
- an issue where modifier keys were not able to be successfully bound
(like Left Shift to `X`)
- improves cursor hiding (except when you use the start menu, this seems
like an SDL issue, see comment)
- Better discarding of kb/mouse inputs when imgui intercepts input
- properly swap bindings when an already set key is assigned, even if it
crosses the distinction of an analog vs normal button
Fixes#2800
