Changeset 16485 for branches/2520_PersistenceReintegration/HeuristicLab.Persistence/3.3/Transformers

#2520 replaced static type registration in HL.Persistence plugin with the KnownStorableTypesMap which is discovered and used by HEAL.Fossil.
As a consequence we do not need to explicitly call type registration for unit tests.
This change has been necessary because on the first access of StaticCache all StoraleTypes are registered. However, when the HL.Persistence plugin is loaded we have not yet loaded all plugins and as a consequence we would miss StorableTypes.