As required by RC, It would help to monitor the full range of the reconstructed PVz, to monitor the SMOG-to-pp vertices fraction.
This MR drops the double PVz histogram we had before (one for pp, one for SMOG), and instantiates it only once. For pp monitoring, only [-200, 200] is selected for displaying in histoyml
The following plot is obtained by running this branch on pp+pAr MEPs
