vesa & framebuffer accelerants: Drop engine hook stubs.

We don't need to provide them after the previous commit.

Bring back the framebuffer driver and accelerant.

This reverts commit 72fc5e6a71075dd28de47514d93bdd80065203b0.

They were removed because app_server often picked them instead of
a better graphics driver, and fallbacks merged into VESA instead.
That seems to have created more problems than it solved, in the long run,
and so the intent now is to change app_server to understand the
framebuffer driver as a fallback one instead.

Change-Id: I6edd97fb29ed2b9c13c6c540569695c8426ecfd7
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4614
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

Add a dumb framebuffer driver.

This is separate to the VESA driver, as the VESA driver requires
using the VBE BIOS. Under UEFI, we don't have the VBE BIOS, nor
are we able to switch modes after leaving UEFI Boot Services, so
a dumb framebuffer driver seemed like the easier way to approach
the problem.

The framebuffer & vesa drivers now test for the presence of the
VESA_MODES_BOOT_INFO boot item to distinguish between which driver
to use. Also added check for the VESA mode count to determine
whether to add the VESA_MODES_BOOT_INFO item.

UEFI video updated to explicitly zero out the VESA and EDID
boot data.