Implement input binding and action system.

[atskas]

A necessity for the input module.

[Tweety-Lab]

Will give it a thorough look sometime soon but at a quick glance I have a few notes:

• Make sure there're bindings for VR
• Think about different types of input, boolean for key presses, floats for triggers, Vector2 for joysticks.
• Think about how a user might want to bind WASD and the joystick to be a movement vector. WASD bindings are booleans, joystick is a vector, how do we solve this so the user can simply query a "movement" binding for a movement vector?

I'd say take some inspiration from Godot's input binding for the last points:
https://docs.godotengine.org/en/stable/tutorials/inputs/input_examples.html