An empty (but valid formed) groups list provided via the OIDC ID token
would be considered as a lacking detail, and therefore trigger a lookup
to the userinfo endpoint in an attempt to get that information.
This fixes this to properly distinguish between not-provided and empty
state, to avoid userinfo where provided as valid but empty.
Includes test to cover.
For #5101
Wrapped userinfo response in its own class for additional handling and
validation.
Updated userdetails to take abstract claim data, to be populated by
either userinfo data or id token data.
Allows a proper defined object instead of an array an extracts related
logic out of OidcService.
Updated userinfo to only be called if we're missing details.
