Add security to test_server

[robinmackaij]

To allow functional testing for 401 / 403 scenarios and the security options (user/password, auth, token) the test_server should implement the desired security options.

Desired support:

• "open" endpoints
• authenticated endpoints
• role- or user-based authorized methods on endpoints (e.g. delete only by "admin")

Useful links:
https://blog.miguelgrinberg.com/post/api-authentication-with-tokens
https://christophergs.com/tutorials/ultimate-fastapi-tutorial-pt-10-auth-jwt/