Removal of the TestUserDAO and UserProvider classes

+ Cleanup of affected tests (primarily within the Repo and Services-Repo projects)
+ Bootstrapping of additional, non-production test users
+ Disambiguation of auth.User to NewUser

See https://sagebionetworks.jira.com/browse/PLFM-2183 and https://sagebionetworks.jira.com/browse/PLFM-2185