Consolidation of PrHit & Cluster types
There are many cluster types around, with some of them carrying around obsolete properties.
Following Moore!2754 and in particular the discussion in !3708 (comment 7802890), it's good to clean up and streamline these clusters to (1) help the use of them by the algorithms, providing easily the information required, and (2) minimize the use of converters in the standard reconstruction workflow, (3) remove obsolete properties.
This issue is mostly to form a plan for (1) and (2), which can then be implemented.