Add new validator that applies data_api_client.email_is_valid_for_admin_user to field
Add new validator that applies data_api_client.email_is_valid_for_admin_user to field

alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend