Auto confirm email when email domain matches Identity Providers domain

Under specific use case scenarios we need to have Enrolment Flows which require email confirmation but allow skipping if the email is already confirmed.
This could happen if:

• The email's domain match the domain of the Identity Provider. For example if i enrol using the GRNET IdP and the email provided by the IdP share the same domain with the IdP, then we can safely assume that this email is confirmed.
• The proxy provides a custom attribute, e.g. email_verified, which the registry can understand and will trigger specific actions. Something similar to email_verified found in OIDC