Update L1Sim trigger tests and configuration to enable Phase-I testing
- Rename "emptyMenu" tests to "L1SimOnly"
- Improve naming and consistent use of flags steering Phase-I and Legacy LVL1 simulation/decoding
- Add new test "L1SimOnly_phase1" with enableL1Phase1=True
- Configure Phase-I MUCTPI simulation in Lvl1SimulationConfig (adapted from !31118 (merged))
- Add dummy xAOD::MuonRoIContainer output in the TrigT1MuctpiPhase1 tool
- Other minor updates in TrigT1MuctpiPhase1
Related Jira: ATR-21568