Implement UEFI

[AnErrupTion]

UEFI should be implemented as it has several major advantages compared to legacy BIOS.

So, in the future, it should be able to completely replace legacy BIOS. The idea is to have a Mosa.DeviceSystem.UEFI class, with a SystemTable struct that should be able to be filled at the bootloader stage, or somewhere around there. The System Table is a UEFI-specific struct that carries many useful information like pointers to ACPI tables, basic Console In and Out handles (though the user should use a graphical console), and of course many more.

Why should it completely replace legacy BIOS? Well, it would be too much of a hassle to support, and in the future, less and less computers will have legacy BIOS supported (most new motherboards and laptops only ship with UEFI now).

This would also mean removal of VBE support in favor of GOP (its new equivalent). It can handle higher resolutions, and is general better.

Now this is obviously my idea, and if you don't agree with it, feel free to comment on what instead should happen.

[AnErrupTion]

See #1040.