Trigger: implement rewriteLVL1 feature in CA

Migrate the rewriteLVL modifier to CA. But instead of introducing yet another flag, we assume that when the LVL1 simulation (Trigger.doLVL1) and BS-writing (Trigger.writeBS) is enabled, we always want to write out the updated LVL1 result.

In order for this to work in athenaHLT a few additional changes were required:

• Enable BS-writing by default.
• Peek into globals if doL1Sim is set. This could be avoided if all ART tests are migrated to set flags.Trigger.doLVL1 directly.
• Set default EDMVersion=3.

Relates to ATR-26582.

HLT/Trigger/TrigControl/TrigPSC/python/PscDefaultFlags.py

@@ -22,6 +22,8 @@ def setDefaultOnlineFlagsNewStyle(flags):
     flags.Input.Format = Format.BS
     flags.Trigger.doHLT = True  # This distinguishes the HLT setup from online reco (GM, EventDisplay)
     flags.Trigger.Online.isPartition = True  # athenaHLT and partition at P1
+    flags.Trigger.EDMVersion = 3
+    flags.Trigger.writeBS = True
     flags.Scheduler.ShowDataDeps = False
     flags.Scheduler.ShowControlFlow = False
     flags.Scheduler.ShowDataFlow = False