UEFI: Ditch console mode setting, choose optimal GOP mode later in boot

boot1 is too early to be deciding a good resolution. Console modes don't map
cleanly/predictably to actual screen resolutions, and GOP does not reflect
the actual screen resolution after a console mode change. Rip it out.

Add an efi-autoresizecons command to loader to choose an optimal screen
resolution based on the current environment. We'll explicitly execute this
later, preferably before we draw anything of value but after we load config
and pick up any tunables we may need to decide where we're going.

This method also allows us to actually pass the correct framebuffer
information on to the kernel.

UGA autoresizing is not implemented because it doesn't have the kind of mode
enumeration that GOP does. If an interested person with relevant hardware
could get in contact, we can take a look at implementing UGA autoresize.

This effectively "fixes" the breakage caused by r327058, but doesn't
actually set the resolution correctly until the interpreter calls
efi-autoresizcons. The lualoader version of this has been included for
reference; the forth equivalent will follow.

Reviewed by: imp (with some hestitation), manu
Differential Revision: https://reviews.freebsd.org/D14788