Replacement for MCTupleTools
Goes with Rec!2652 (merged) and LHCb!3397 (merged) and DaVinci!646 (merged)
Sits on top of LHCb!3391 (merged).
Related to Rec!2677 (merged) and part of lhcb-dpa/project#145.
See discussion of functor collections at https://gitlab.cern.ch/lhcb-dpa/project/-/issues/178.