Add a Keyboard Driver to improve keyboard functionality

[JosephMichels]

Adds a keyboard driver that keeps track of key state and allows keys being held down to register correctly as a button being held down.

This implementation changes the input channel to consider 3 input sources.

• Gamepad (Gamepad.ts)
• Keyboard (Keyboard.ts)
• AdHoc - Input triggered from the UI (Input.ts pressButton())

And merge them together into a final InputFrame that will be queued up.

This is an associated pull request for xbox-xcloud-client that implements the needed changes there to remove its keyboard functionality since it is now located here.