Dropped GeoLArHit
The benefits coming from the usage of this class are rather questionable. On the other hand, it uses AthenaMT-unfriendly way of retrieving a pointer to the CaloDetDescrManager and caching it.
The clients of GeoLArHit had been switched to the direct usage of LArHit and CaloDetDescrManager interfaces, and subsequently, the GeoLArHit class was dropped.
The migration of individual client classes were implemented in separate commits in order to facilitate the code review.