Add Messaging Data to Chat API

Feature Request Summary: 

The recently released Messaging Dataset in Explore should be made available as part of the Chat API.

Description/Use Cases: 

We need to be able to pull all of our Zendesk data into Looker and incorporate as part of existing company dashboards, as well as analyze along side of order data. 

Business impact of limitation or missing feature:

It is very frustrating and difficult to not be able to report on everything in Looker. We cannot see a complete picture of our support SLAs and overall health of service that we can share with other stakeholders. Not everyone has Zendesk and we like to marry our Zendesk data with other company data.