Implement the VGA Text console for the `x86` port

[alexandruradovici]

Implement the Text VGA console for the x86 port and use it instead of the serial port. Use https://en.wikipedia.org/wiki/VGA_text_mode as documentation.

• implement the Text VGA peripheral
• modify the qemu command to start the Text VGA
• Implement the Transmit UART trait for the Text VGA
• set the kernel debugger to the Text VGA console
• document the available console in README.md

[Joan-DwD]

#24 Implement keyboard support as a Receiver for x86 Issue has to be finished before this one is done.