WIP: Mobile engagement automation needs to have a generic set of schemas that support push, in-app and message

## What are the schemas that are affected by the issue
context\pushNotificationToken.schema.json
context\profile.schema.json

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

The current Push Notification Token schema is limiting in this area. It really needs to be under an Application construct where 1)Push, 2) In-App and 3) Message oriented communications are supported.

This is a breaking change to Profile.

Start by reading context\pushNotificationToken.schema.json and context\profile.schema.json, then review how Campaign and Mobile Engagement Automation use them. The issue proposes an Application construct supporting push, in-app, and message communications; done means defining and documenting the affected generic schemas while accounting for the breaking Profile change.

Written by the indexing model from the issue text.