EDIT

solving multiple representation probelms when adding source references to MediaSpecimen

• extending PersistentContextAnalyzer
• EntityCache support for more than one base entities

ref #7059 ref #7046 using kindOfunit for TypeDesisgnations instead of DerivationEvent type and fixing save and LIE problems:
- intoducing EntityCache to allow re-using previously loaded entities
- CdmEntityCache implements EntityCache
- ToOneRelatedEntityReloader to replace entities loaded by the LazySelect...