Test API auth

[Rutherther]

• all types of duplicates
• teachers
• bachelor, master, doctor
• all roles should be assigned in correct cases
• if every request to kos or usermap is made only once and then cached
• if auth role processor will ever handle more things at once (maybe add check for stop after assigning roles?)
• only same ctu username should be allowed if it was already set
• errors of kos or usermap apis should be logged as warnings, but should not throw exceptions

[Rutherther]

Unit tests could be written for each condition, step, task, the process.

Xunit, Moq will probably be the best choices.
https://github.com/JonPSmith/EfCore.TestSupport

This may be done after rewriting KosApi and UsermapApi to be more suitable to testing. I think the best approach will be to make them similar to how Remora handles it (create IUsermapPeopleApi, UsermapPeopleApi, CachingPeopleApi)

To test the whole process, integration tests for testing: duplicities won't be allowed if they shouldn't, user with both duplicity will get deleted, the process completes successfully along with saving all needed data and assigning roles.