Returns the registration status for the given account for the given carrier
{- "carrier_account": "99dc410d295b4a168993cc38809cb123",
- "object_created": "2019-08-24T14:15:22Z",
- "object_owner": "tom@gmail.com",
- "object_updated": "2019-08-24T14:15:22Z",
- "status": "PENDING_TERMS"
}