prepare FwdEl HLT integration

Updates requested in MR !53228 (merged) to allow for a later integration with HLT

TriggerEDMRun3.py: * added jFexFwdElRoIContainer#L1_jFexFwdElRoI added jFexFwdElRoIAuxContainer#L1_jFexFwdElRoIAux.thresholdPatterns

HLTEDMCreator.h: added jFexFwdElRoIContainer

*also tentatively added TrigRoiDescriptorCollection#HLT_jEMRoIs but so far this line is commented out

I chose the label Run3L1Calo