Implement keyboard support as a `Receiver` for `x86`

[alexandruradovici]

Use the 8042 driver, implement the Receiver trait for the keyboard.

• implement the Receiver

[domnudragota]

I suggest creating another sub-issue to implement the process console on VGA. Firstly we need to make sure the keyboard actually sends commands to 8042 before porting everything over to VGA. #36