New schema to support direct marketing subscriptions

## What are the schemas that are affected by the issue
Profile

## What are examples of products that are impacted by the issue
Campaign

New schema to register subscribes and unsubscribes to directly marketing lists

Start by reviewing the Profile and Campaign schemas referenced in the issue. Clarify the required fields and behavior for registering subscriptions and unsubscribes to direct marketing lists; done means the agreed new schema is defined and supports both operations.

Written by the indexing model from the issue text.