bootloader video_text_console: Refactor into the new ConsoleNode model.

Change-Id: I3dc59cbdfd28f1ada49b02e42d50ec2b52c40227
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4643
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

bootloader: Refactor console functions into the VFS ConsoleNode class.

This way it becomes much easier to write multiple console implementations
in one bootloader.

Tested for bios_ia32 and efi.

Change-Id: I67134f5c3de109b15d46898864ba7f51c6592afc
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4642
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

boot_loader: Add a video_text_console for potential use by bootloaders.

This uses the frame buffer console that KDL uses. It needs some work,
though, as the frame_buffer_console colors system is not quite compatible.