Adde introspect token from server

[alexzemlyakov]

For now get_current_user just parse current token without update it from keycloak server. It would be good to introspect token data directly from server. This would help deactivate the user or change the list of his roles immediately after his deactivation on the keycloak server.

[yannicschroeer]

We're open to pull requests but do not have the time to actively develop features