link are checking that email matches, +email alias are normalize into email
if email is already used on another account, link is not possible
not usurpation risk as the IDP is choosen by the admin
- ensure Oxicloud s correctly functional with OIDC login
- refresh token works
- givenname, familyname, picture are imported in users' informations
- test relogin (server is not using same path)
- test email verified
- test admin group provided from IdP