R1:282e37aaf682

Do not expose Contact Numbers settings panel when no SMS support configured

Summary:
It's useless without SMS support and only exposed to the user themselves.

Closes T15486

Test Plan:
Before and after applying this patch,
* Try to access the list of your contact numbers at `/settings/panel/contact/`
* Try to access an existing, previously created contact number at `/auth/contact/1/`
* Try to add a contact number at `/auth/contact/edit/`
* Go to e.g. `/settings/panel/datetime` and check the…