Add functors to get the number of hits in regions of the muon stations
Will be used in Moore!2975 (merged) and lhcb-datapkg/ParamFiles!67 (merged)
Adds functors to get from the TES the number of hits in stations/regions of the muon stations. Used in Moore!2975 (merged) (which also requires ParamFiles!67). Work done mostly by @hartmanl
Edited by Louis Henry