Improved Input Menu

[zicklag]

Description

We want to re-organize the input settings menu a little bit.

For every kind of input, i.e., keyboard 1, keyboard 2, gamepad 1, gamepad 2, etc. we want to have a page that has the controls just for that input, instead of laying everything out in a table.

I'm thinking of having left and right arrow buttons for switching between the different kinds of inputs.

Alternatives & Prior Art

Input menu initially added in #100 with the topic of alternative layout initially brought up here: #100 (review).