Review checker (MC-based) algorithms in Tr/TrackMonitors

See discussion by @decianm.

VPTrackMonitor is currently in Tr/TrackMonitors but it uses MC information (and it is not the only case). Such algorithms are nominally called "checkers" and live in a separate package (e.g. in Pr/PrMCTools or Tr/TrackCheckers).

Some modernization is also welcome in VPTrackMonitor (and probably other similar checkers). See also the related #135