User management for Classifier

[turnerrainer]

AS A Product Owner
I WANT TO have the functionality for user management for Classifier
SO THAT their permissions, etc. could be maintained

Acceptance Criteria

• Re-using Bürokratt's current user management GUI as part of Bürokatt Backoffice

• Classifier-specific user permissions added to generic Bürokratt's user management

• Classifier-specific user management on back-end level is not foreseen
• Existing user management- and permission-specific backend solutions are used