Add missing "core" ThOr functors

There are a few commonly-used LoKi functors that do not yet have ThOr equivalents. For example:

• proper lifetime with respect to the "best" primary vertex
• functors to interact with "extra info" (see LHCb#106), for example reading saved selection or isolation MVA values
• functors to do with changing assigned mass hypotheses
• ID, ABSID and possibly other functors accessing true ID information
• [other missing functors to be filled in here]

The range of functors used in the Run 2 trigger was surveyed in this talk.

At this stage of ThOr/LoKi cross-validation these should probably be implemented with an (if constexpr) branch on LHCb::Particle, although this can be dropped in due course.

DPA gitlab has a more complete list of missing functors, https://gitlab.cern.ch/lhcb-dpa/project/-/issues/61, please use this issue from now on.