Rename OriginatingClient to DomainType and convert into a JSON enum
Add the PrincipalHeader classes and enums
Add DAO for prefix filtering on various parts of principal names and identifiers
The data for this table will be filled in by other workers/processes/beans.
Various test changes
Remove a few unnecessary components of the prefix table (such as migration and a complex-ish return type)
Add a worker to monitor principal change messages.
Add change messages to UserGroup and UserProfile (not all operations, just the ones that might involve data changes).