Add support for revoking access tokens when using KeyCloak Authenticator

[Ernstsen]

Describe the feature

Enabling logging users out through the OIDC API when using keycloak as the OAUth2 provider

Use cases

When using KeyCloack OAuth2 provider

• Attempting to sign a user out through the API, in compliance with OIDC

Contribution

Implementatin of the feature is proposed on PR #661