Was accidentally skipped during previous updates. Will now be used on
saml, ldap & standard registration where required.
Uses session to know if the email was just sent and, if so, show the
confirmation route.
Was preventing any other registration actions from taking place such as
LDAP/SAML group sync. Email confirmation should be actioned by
middleware on post-registration redirect.
Added testing to cover.
Tested for LDAP, SAML and normal registration with email confirmation
required to ensure flows work as expected.
Fixes#2082
