WIP: TLA test chain

This MR contains the changes needed to implement a jet TLA (ATR-20395). So far, the threshold of the chain added (L1_J15) and its parameters (only keeping the first 10 jets as long as their pT is > 20 GeV) are for testing purposes. This has been tested with a sparse commit of yesterday morning's master on Athena/22.0.16 x86_64-centos7-gcc8-opt, nightly at /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-13T2138.

Known issues/discussion points:

1. no L1_J15 seems to pass in 2000 events of EnhancedBias, so the tests from https://twiki.cern.ch/twiki/bin/viewauth/Atlas/TriggerMenuMTPackageInstructions have worked in MC only. We haven't investigated this yet, since running the full menu with the set of packages we have fails with an error in TrigCaloRec that seems to have been understood since (ATR-20042?). Running the jet slice [1] with a menu containing only the TLA trigger will work.
2. potential code duplication between TrigJetTLAHypoAlgMT and TrigJetHypoAlgMT (can be refactored)
3. some of the chain parameters are still left as defaults but we will fix this later
4. the scope of the InputMaker used for this chain should be discussed with @tamartin

We don't necessarily expect this MR to be merged yet, it's more of a starting point for code discussions towards the final implementation.

Thanks, Caterina, @khoo and @boveia

[1] athena.py -l DEBUG -c "setMenu='LS2_v1'; forceEnableAllChains=True;doEmptyMenu=True;doJetSlice=True;doWriteBS=True;doWriteRDOTrigger=False;" --imf --perfmon --threads=1 --evtMax=1 --filesInput=/cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/TriggerTest/valid1.410000.PowhegPythiaEvtGen_P2012_ttbar_hdamp172p5_nonallhad.merge.RDO.e4993_s3214_r11315/RDO.17533168._000001.pool.root.1 TriggerJobOpts/runHLT_standalone.py