Better Gamepad support

[hobnob]

We've come a long way in Gamepad support, but it could probably be better. The vague idea I have at the moment is that we map common gamepad types (Xbox, Playstation, Switch) and allow events to be fired based on those peripherals. For example, a Gampad.Button enum could be be used to determine if X, Y, A, B, □, △, or ○ were pressed using a GamepadEvent.ButtonDown. Each Gamepad could likewise have a GamepadType enum to determine what sort of gamepad it is (again, Xbox, Playstation, Switch), and some types could support orientation (such as a Switch controller)

I'm not entirely sold on that concept or completely sure of all the technical feasabilities, but certainly something like it.