Keycloak server supporting OAuth client credentials flow

Keycloak dev server will be used for issuance of tokens between services during development in the docker-compose environment.

Each service must have its own client_id and client_secret and will use them to obtain bearer tokens. They will be used when making requests to other services.

It's best if the Keycloak is automatically initialized with client credentials for all services in the workspace, so everything can work out of the box with authentication.

Note: If it turns out that Keycloak is not developer-friendly in docker-compose environment, a mocked OAuth server can be created to issue tokens for testing purposes.