Feat : audit trail with uri

The audit trail was using a Keycloak specific uri extracted from the Keycloak token. This PR integrates a connection between the audit trail and the knowledge base. In this manner the PEP sends the authentification token to the audit trail to get the audit trail events (API). From this token, the audit trail extracts the Keycloak identifier and sends a SPARQL query to the KB to get the corresponding URI for that user. The audit trail then returns the events for the user URI.

Code tested with the playground locally: it is functional.