resumeWithAuthCode
Called after getting the redirect back from the authorization server to the credential issuer.
Will request a token, and use that token to request a credential and store it.
Prefers building the token request by using scope (from SupportedCredentialFormat), as advised in OpenID4VC HAIP, but falls back to authorization details if needed.
Parameters
url
the URL as it has been redirected back from the authorization server, i.e. containing param code