TriggerJobOpts: cleanup TriggerConfigGetter and flags

This is rather big cleanup of TriggerConfigGetter:

• Replace TriggerFlags.dataTakingConditions by ConfigFlags.Trigger.availableRecoMetadata: this flag is used to indicate the trigger systems that are enabled during reconstruction. It is set based on the L1/HLT keys in COOL or the metadata in the input file.
• Remove obsolete metadataItems setting as discussed with @tamartin (the key names are not relevant anymore, and we are setting this elsewhere already).
• Deprecate TriggerFlags.configForStartup: this flag was used to indicate whether trigger keys can be found in COOL. But this is essentially the same check as availableRecoMetadata performs already. The flag itself is still there but will print a WARNING if set. Once this is merged, should update reprocessing shifter instructions to not add this to the AMI tag anymore (discussed with @mark).
• Fix the broken getKeysFromCool method in TrigConfigSvc.

I did not re-implement the setting of the DQMonFlags based on the available systems. If this is really needed still for the legacy monitoring it should be done in the relevant DQ job options. There are also a few TODO items left in the code that will be cleaned up separately. And once the dust has settled, we can think about migrating this to CA.

Relates to ATR-23102.

cc @rbielski

Trigger/TrigConfiguration/TrigConfigSvc/python/TriggerConfigAccess.py

-# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 
 from .TrigConfigSvcCfg import getTrigConfigFromFlag, getL1MenuFileName, getHLTMenuFileName, getL1PrescalesSetFileName, getHLTPrescalesSetFileName, getBunchGroupSetFileName, getHLTJobOptionsFileName, getHLTMonitoringFileName
 
 from TrigConfIO.L1TriggerConfigAccess import L1MenuAccess, L1PrescalesSetAccess, BunchGroupSetAccess
 from TrigConfIO.HLTTriggerConfigAccess import HLTMenuAccess, HLTPrescalesSetAccess, HLTJobOptionsAccess, HLTMonitoringAccess
 
-from PyUtils.Decorators import memoize
+from functools import lru_cache
 
 """
 Access to the trigger configuration in python is provided depending on
@@ -40,9 +40,11 @@ are then loaded from the DB.
 
 """
 
-@memoize
+@lru_cache(maxsize=None)
 def getKeysFromCool(runNr, lbNr = 0):
-    from TrigConfStorage import TriggerCoolUtil
+    """Return dictionary of trigger keys for given run and lumiblock number
+    """
+    from TrigConfStorage.TriggerCoolUtil import TriggerCoolUtil
     condb = "CONDBR2" if runNr > 236108 else "COMP200"
     db = TriggerCoolUtil.GetConnection(condb)
     run_range = [[runNr,runNr]]
@@ -64,7 +66,7 @@ def getKeysFromCool(runNr, lbNr = 0):
     dbaliasMapping = { "TRIGGERDBR2R" : "TRIGGERDB",
                        "TRIGGERDBV2" : "TRIGGERDB_RUN1" }
     if d["DB"] in dbaliasMapping:
-        d["DB"] = dbaliasMapping[ db["DB"] ]
+        d["DB"] = dbaliasMapping[ d["DB"] ]
 
     return d
 
@@ -220,4 +222,4 @@ def getHLTMonitoringAccess( flags = None ):
         raise NotImplementedError("Python access to the trigger configuration (HLT menu) from in-file metadata not yet implemented")
     else:
         raise RuntimeError("Unknown source of trigger configuration: %s" % tc["SOURCE"])
-    return cfg
\ No newline at end of file
+    return cfg