ART Tests have been updated to only run for certain branch/project
combinations and have also been updated to save output root files
where useful.


Former-commit-id: 5899b8d6743cd4545a78fcb8adbba48665f282ea

Former-commit-id: 25df8d46b0a779bc83efd67c52fac6fa4231a242

Initially adding jobs for AtlasG4_tf.py (single-threaded) and Sim_tf.py FullG4 (single-threaded).
See discussion in !6876.


Former-commit-id: 61b3ce24caf0540eb207c4fff4eb2acf6d70c7f7