Duplicate the X11 testsuite into x11full and x11bare.
Run both of them in the Fedora CI runner.

For now they do the same thing (followup commits will change that), but
the goal is to have 2 testruns:

x11full should get as close to simulating a modern full-featured setup
with a compositing WM and all extensions.

x11bare should have the minimum required setup that te testsuite needs,
but nothing more. No compositor, a WM wit the minimal set of features,
etc.