Implementation of cut on the distance from PV found by ZFinder in HMT chains
These changes allow for applying a cut on the distance of the track from PV found by ZFinder when counting tracks for HMT triggers.
The value of 10mm (very loose) was found experimentally by looking at the distance of vertex found by ZFinder to the PV found offline.
A minimal change of counts is inserved in the test.
The expected followup is tuning of vertex weight thresholds.