Improvements for rbac

Description

The first version of rbac is pretty basic and requires some improvements.

TODO:

• Secure stored passwords (https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html#argon2id)
  • https://pkg.go.dev/golang.org/x/crypto@v0.0.0-20220427172511-eb4f295cb31f/argon2
  • https://pkg.go.dev/golang.org/x/crypto/bcrypt
• Add session handling including proper log out function
• Remove authorization away from auth_interceptor, probably in some kind of rbac service (see !287 (comment 234649))
• Move user and role management related stuff away from gRPC auth service
• Set secret and duration data for jwt tokens in config (see !287 (comment 234650) and !287 (comment 234657))
• Provide an interface to support different authentication/authorization methods
• Check that non-admins can only create one user with lowest permissions and can only change their own user or role
• Check that non-logged in users can only create one user with lowest permissions
• Remove option for non-admins to create users