Adding TP Separation for LUCID_SimHitCollection to 21.0
This had been partially implemented, but never completed.
This is a sweep from a similar commit to the master branch (!40868 (merged)) the only difference is
that this version writes out LUCID_SimHitCollection_p1
rather than LUCID_SimHitCollection_p2
.
Doing this now as the HepMC3 migration in master would otherwise prevent master reading LUCID hits written in 21.0.
Edited by John Derek Chapman