This refactors the `UpstreamOIDCIdentityProviderI` interface and its implementations to pass ID token claims through a `*oidctypes.Token` return parameter rather than as a third return parameter.
Signed-off-by: Matt Moyer <moyerm@vmware.com>
We missed this in the original interface specification, but the `grant_type=authorization_code` requires it, per RFC6749 (https://tools.ietf.org/html/rfc6749#section-4.1.3).
Signed-off-by: Matt Moyer <moyerm@vmware.com>
