Memory leak during transaction handling

[novoj]

evitaDB leaks memory when there are regular catalog updates in transactional mode. By studying heap dump we found that problem is inside catalogAccessor lambda in EntityCollection. It seems there are situations where collections refer to the old catalog which in turn refers to old entity collections which in turn refer to yet older catalog instance and vice versa.

Current way of reataching entity collections to new instances of the catalogs seems unreliable and we have to change it.