Updates to primary vertexing performance plots
This MR includes the following modifications:
- refactoring of code for evaluating zReco - zTruth for PVs, including resolution helper histogram used by the IDPVM postprocessing step
- addition of useful hs vertex selection efficiency plots when considering non full pileup truth samples
- removing of duplicated code
- removing of return condition over quantity not used, that was biasing the HS vertex selection efficiency plots - see https://indico.cern.ch/event/1345638/contributions/5695495/attachments/2763341/4813481/20231201_HSeff_IDPVM.pdf for more details