init sql file: removed unnecessary constraints and renamed field names.
entities: replaced german comments, added missing annotations
and configurations, also renamed fields for db schema
fixed unit test for to scim mapping in user entity spec
[enhancement] extracted scim to entity conversion for user to own
service
[test] added test for new Scimconverter service
[cleanup] removed unsued annotation
[cleanup] renamed field for urn
[test] fixed tests to reflect new ScimConverter
[cleanup] removed superfluous test code
[enhancement] added Extension DAO
[cleanup+test] changed name of setters/getter to reflect new name of member
[test] fixed test to reflect new Extension DAO
[enhancement] added FetchType eager
[enhancement] added @Transactional to class
[fix] now using existing ExtensionEntity from DB instead of constructing
new one