v2 Metrics - Analytics

- [x] Number of sessions - total and per user
- [x] Position in menu where each user drops off
- [x] Number of sessions needed to complete registration per user
- [x] Responses to each question per user
- [x] Number of moms registered per facility/nurse phone
- [x] Reasons for optout per person
- [x] Log registered_by against contact for CHW and clinic lines when registered by someone else