This should have been done when reworking Workstation,
but better that late than making a copy for Education.

NB: directory name has been chosen to both sort late
    (so that functionality related checkboxes come first
    and graphics setup related ones sit down there), and
    to relate to X11 as well.

Four checkboxes with "Elbrus 801-PC" prefix look a bit too much,
let's put these under a parent one; the counter-argument is that
selecting that parent checkbox is going to provide message telling
that there are conflicts within -- the proper widget would be a
dropbox with the number of seats but we don't do that just yet
in alterator-pkg.

The autologin group goes there too; still a hack that should be
replaced by proper alterator-users multiseat support.

I've shipped modesetting-based images and mga2-based ones
(and reverted to modesetting by hand "when it MUST work");
let's just do it right.

NB: found out that Name fields must NOT contain ";"
    or alterator-apt chokes in runtime (not fatal
    but still spectacular, see #35526).