vesad: Changing the tty shortcuts

https://gitlab.redox-os.org/redox-os/drivers/blob/3f41225d78eb2b403ecb2cd8bada1da92f8ec34f/vesad/src/scheme.rs#L229-240

The vesad daemon currently uses F1-F12 to switch between ttys and as a result it swallows every event of these keys. This is a problem, there are multiple ports that would use the function keys (scummvm, dosbox, schismtracker, vice, etc.)

What about changing the shortcuts to Meta+F1 - Meta+F12?