Implement authentication for user data endpoint

[seluianova]

Is your feature request related to a problem? Please describe.
Client authentication must be implemented for the user data endpoint.
It should be only valid for one ProjektID.

Describe the solution you'd like
Authentication method is to be defined.
Possible options:

• TLS Client Certificate (preferred)
• HTTP Basic Authentication

Describe alternatives you've considered
TBD

Additional context
Add any other context or screenshots about the feature request here.

#blocked by #1491

[f1sh1918]

@seluianova i added blocked since we can not create tokens yet, but it could also be done with a hardcoded token for the moment if we don't enable it for production