Ground work for decoding Run-3 Level-1 RoIs from ByteStream to xAOD

Implementing framework code for Run-3 L1 RoI decoding following the ideas outlined in ATR-20745. New algorithm L1TriggerResultMaker is added which creates an xAOD::TrigComposite object named L1TriggerResult and calls converter tools to create xAOD RoIs from BS and link them to the result. A converter tool interface is provided along with an example implementation decoding muon RoIs (filling with dummy information). A hook to the new object is implemented in the L1Decoder and the corresponding python configuration. No actual interpretation of the new RoIs is made yet in the L1Decoder, as sub-system developers have to first implement their decoders to provide those RoIs.

The configuration is implemented in a way not changing the current default workflow. In order to test the new code, one has to set the decodePhaseIL1 flag in testHLT_MT.py. The code was tested with the following command:

athenaHLT.py -l DEBUG -c "decodePhaseIL1=True" -n 15 -f /cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/TrigP1Test/data18_13TeV.00360026.physics_EnhancedBias.merge.RAW._lb0151._SFO-1._0001.1 TrigUpgradeTest/full_menu.py

and works as expected.