Fixes and additions to IDPVM
This MR introduces the following changes:
- hs vertex reco efficiency definition corrected: no more flagging as not reconstructed a vertex that is the one best matched to the true HS vertex, but not the closest to it
- hs vertex reco + selection efficiency: now filling the histogram in the if condition of the vertex reconstructed
- hs vertex reco, selection, reco+selection efficiency: new plots, shown as a function of the number of true interactions
- new plots for number of true interactions and local pu density