The point of this task is to:

• Make sure that request parameters and response parameters are aligned with token exchange specification: https://datatracker.ietf.org/doc/html/rfc8693
• Request parameters marked in the specification as REQUIRED are REQUIRED also in Keycloak
• Response parameters marked in the specification as REQUIRED (or ideally also RECOMMENDED) are present in the response by Keycloak
• We do not add any non-standard parameters to the response. We may possibly add non-standard parameters if we add them in other grants as well (EG. in OIDC authentication response).

Will be good to have some tests for this (Required parameters etc) unless we test this already?