Run these tests in their own merge requests

Addition of some CI so these cern tests run in merge requests like this one.

The whole set of systemd-resolved tests were merged too soon yesterday and it would have caught that.

It has deficiencies since upstream centos tests are not executed first but still its a useful tool for developing tests. If these tests pass but then fail in full run of upstream+cern then we no its some bad interaction of the two test sets.

• Also re-enable the test reverted in !17 (merged) since image-ci!34 (merged) is now in place.
• Also rename some 1_, 2_, ... tests as 01_, 02_ as they were running after the 10_ ... tests.

In the test run we see

[+] Thu Sep 25 10:32:42 AM CEST 2025 -> Running ./tests/cern_basic/11_systemd_resolved.sh - Checking localhost fqdn lookup is from network

So we know it this branch of tests that is running.

Also there was a test which again breaks the /etc/hosts - I removed it since its not a test and not obvious why its there - apparently not needed.

Comments:

• If we wanted to reduce the output really need to get rid of the "yum list" not sure its very useful.
• Will add container tests after as well but this already is a much bigger patch than I planned.