[SUBTASK]-Add Login Method to Userrepository

[SturmDerLiebe]

Ressources

• Mock API: https://www.mockaroo.com/apis
  • Credentials in Slack -> Resources

Tasks

1. Check if Preview Server is already public with login Endpoint (likely not)
   1. Temporarily create Mock Endpoint in Mockaroo (See Mock API Resource)
2. Implement the login method similar to UserRepository.registerUser
   3. Make sure to call _hanldeResponseAfterAuthentication to handle caching the SessionId