keyboard shortcuts: use code for detection and key for display

**Describe the bug**
tldr the "W key" is in the same place on every keyboard and key mapping is done in software - code tells you the physical button name, and key tells you the character that gets emitted when you press that button

User report:

When keybinding with my AZERTY keyboard the camera movement as ZQSD, it still shows WASD. And when I set to null and then bind with Z (for example), it still shows W. So it's not an issue of not changing the key, but an issue of not binding the correct key. I don't want my up being at the bottom of the keyboard, my left on the top, and the two other somewhere in the middle, I want to actually use the + shape as in every other games.