More flexible configuration for PersistReco

Quoting @apearce

"Finally, there’s a ‘big picture’ problem I think one could start tackling today: how to merge persistence requests for the same object that want different levels of information. For example in ’normal’ Turbo we don’t persist tracks associated PVs, but in PersistReco Turbo we do. This distinction, between ‘Turbo information’ and ‘PersistReco information’ is hard-coded in the C++ logic, but it’s brittle and will be hard/impossible to extend to more than two ‘levels’ of granularity. As problem is fairly generic we can tackle it today, but it requires some thinking before charging forward."