Support for other keyboard layouts

[roym899]

Is your feature request related to a problem? Please describe.
Navigating in the 3D view using WASD becomes difficult when using, for example, Dvorak or Colemak layout. It would be nice to improve support for other layouts or atleast have some way to change keys via a config file.

Describe the solution you'd like
Ideally some sensible defaults for alternative layouts or an easy way to change keybindings manually.

Describe alternatives you've considered
Probably some per-application mapping tools could be used to work around this externally.

Related to #3055

[emilk]

Instead of using the WSAD logical keys, we should be use the physical keys. Two things on that though:

A) physical keys is not implemented in web yet
B) egui doesn't have convenience methods for "is this physical key currently pressed?"

Both is very solveable though