Full per-button input mapping

[deltaryz]

Being able to map every single individual controller button would allow setups like a single sideways joycon to be used, or something like one-handed setups? Generally there's plenty reasons to do so (broken controller buttons, etc)

Perhaps even some 'presets' would be a neat QoL feature.

[fennectech]

I would also like to see remapping the menu input buttons. As well as the ability to tie multiple buttons to the same input on the gba