TriggerTest: Move almost all remaining legacy trigger test to the TrigValSteering framework
Move almost all remaining tests in Trigger test from the old shell-based scripts to the TrigValSteering framework (ATR-20038). The corresponding shell scripts superseded by the python scripts are removed. Also some unused shell scripts are removed.
The only remaining shell-based tests in TriggerTest will be the id_slice and l1_slice tests, which can be ported in another MR, and the physics_pp_v7_primaries_build test which is currently still used in the CI. The latter will be removed after the CI configuration is updated.
Please look at the two commits separately and don't squash, because git incorrectly shows some remove file + add file actions as a modification.