TrigP1Test: rename all tests and add EmptyMenu tests
This MR consists of two parts:
- Rename all tests in TrigP1Test to comply with the naming convention described in ATR-19735. This has multiple advantages, including being able to run the tests with the
runTrigART.py
script. - Add empty menu tests which are the same as the TrigUpgradeTest empty menu test, but using athenaHLT. Two versions are added - with 1 thread and with 2/2/2 forks/threads/concurrent-events. This is a small step towards having some HLT chains running in the online framework (ATR-19505).