Issue #3099789 by amateescu, Berdir, hchonov, catch, alexpott: Remove the BC layer for revision metadata keys

Issue #2248983 by hchonov, amateescu, paranojik, timmillwood, tstoeckler, catch, Berdir, alexpott: Define the revision metadata base fields in the entity annotation in order for the storage to create them only in the revision table

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits