When a user checks the `accept` checkbox, we will track that
acceptance as usual. That way they don't need to accept again after
they complete the registration.
When an unauthenticated user visits the `/-/users/terms` page, there
is no button to accept, decline or continue. The 'current-user menu'
is also hidden from the top bar.
This allows admins to define terms in the application settings.
Every time the terms are adjusted, a new version is stored and becomes
the 'active' version. This allows tracking which specific version was
accepted by a user.
