HLTSeeding: Add support for combined (eFex+jFex) Tau RoIs
Implement creation of a cTau container containing deep copies of only those eTau objects which match a jTau object. The container is decorated with ElementLinks to the matching jTau. Implement HLT seeding from this new cTau container.
To do later (comments left in the code):
- Replace explicit eTau-jTau matching logic with a to-be-implemented function from L1TopoSim
- Implement the actual threshold pattern logic instead of the placeholder (task for L1Calo experts)