Create a new user management based on keycloak (OAuth)

• 'user' replace the implementation
• new auth API endpoints
• test runs based on a keycloak mockup
• local keycloak via docker compose
• gui uses keycloak for login, logout, links to register, forget password, edit user, etc.
• install a keycloak on labdev
• backup restore for keycloak
• some tests on the real keycloak
• theme keycloak
• additional keycloak attributes
• a cache for get_user
• copy script for existing users to keycloak