Steam Deck: allow keyboard and mouse configuration

The steam deck offers the ability to bind its buttons to keyboard controls, use the built-in trackpad as a mouse, and so on. DST currently only allows binding for the controller mode of the steam deck and doesn't present options like "inventory 1,2,etc", doesn't support mod keys (since those pretty much have a built-in list of selectable keyboard keys and will never directly support steam deck).

I pretty much bought the steam deck to be able to play DST in more places while maintaining the niceties of playing on the PC like all of the mods including geo placement, geodrop, etc. Without the ability for DST to turn off "steam deck" bindings and allow KB&M bindings, I won't be able to enjoy DST on the steam deck like I had hoped. Many others on the forums with a steam deck share this same grievance.

Note this is specifically about the in-game binding selections, not the configurability of the steam deck buttons themselves. It's also not about the ability to bind additional steam deck buttons like R4, R5, etc. We want the ability for DST to configure controls as it does on PC with keyboard and mouse and to use the advanced steam deck controller design to emulate the keyboard presses.