* enforce 2fa policy on removal of second factor
users should be revoked when their second factors are removed.
we want to revoke users so they don't have to be invited again and
organization admins and owners are aware that they no longer have
access.
we make an exception for non-confirmed users to speed up the invitation
process as they would have to be restored before they can accept their
invitation or be confirmed.
if email is enabled, invited users have to add a second factor before
they can accept the invitation to an organization with 2fa policy.
and if it is not enabled that check is done when confirming the user.
* use &str instead of String in log_event()
* enforce the 2fa policy on login
if a user doesn't have a second factor check if they are in an
organization that has the 2fa policy enabled to revoke their access
needed for web-v2023.8.2+ compatibility due to the inclusion of the new
trusted device encryption feature. without this change, the web vault
will assume that you don't have a master password set and force you to
set one.