[ATR-21215] Combo hypo: check prior features
For ATR-21215
Adds an additional uniqueness criteria to the combo hypo.
Tow features, A5 and A2, are considered similar/non-unique if one feature is an earlier version of another, i.e. if the stepwise reconstruction went A1->A2->A3->A4->A5
This is needed to properly count multiplicities in tag-and-probe chains, during the probe steps we are always comparing final-step features on the tag- leg with intermediate-step features on the probe- leg.
The removing of duplicates is then left to the existing de-dupe algorithm.
Changes to HLT_e24_lhmedium_g25_medium_L12EM20VH
reflect that in Step4 additional rejection of photons-which-are-also-electrons is possible here.
Edited by Tim Martin