The non-English tests so far did not test that graphical login
worked as expected, which is a fairly large hole. With this
change, they should do a Workstation install and test login to
both GNOME and the console works as expected. KDE is not yet
tested.
As part of this we tweak the implementation of keyboard layout
switching in graphical environments to use a generic function
in main_common which can handle both anaconda and desktops
(just GNOME at present, but should extend easily to any desktop
with a known switcher key and a visible layout indicator),
replacing the anacondatest class method. I kinda don't like that
the test has to specifically tell the function when it's in
anaconda, but I don't think I want to start experimenting with
a global 'test phase' openQA variable or anything like that at
present.
Fixes T842.