Controls GUI: Expose other actions bound to keys by default

[superuser-does]

The Controls menu should permit players to to view & bind many more keys. The benefit of this is more for discovery instead of actually changing keys.

The only keys I was certain were not bound were the function keys, but there might be more

These are the ones I've mapped and how I'd list them based on the little I know. How to group them is another question

Key	Text for default function
F1	(don't think this is bound)
F2	Toggle edit mode on/off Group this under editor controls
F3	Change map/game mode
F4	Vote on new map/game mode
F5	Server browser
F6	Player setup
F7	(don't think this is bound)
F8	Simplify geometry Group this under editor controls
F9	Toggle first/third person view
F10	Screenshot
F11	Screenshot without HUD
F12	(don't think this is bound)

It should not be possible to configure Esc through the Controls GUI, as it's an important key used for binding other keys.

[qreeves]

Will defer to Q009, as editor controls have extra complications due to modifier keys.