MCHit persistency
In Moore (for both hlt and spruce), we are only packing MCParticles/Vertices. In principle, this should be extended to MCHits of all detectors. The MCHit packers/Unpackers already exist so it's just matter of adding them to persistency configuration.
Follow up from https://gitlab.cern.ch/lhcb-dpa/project/-/issues/79