Ability to retrieve last_seen data per product via REST API

Summary

For ease of minimizing the number of licenses, organization admins want to retrieve the last seen data via REST API.

Steps to Reproduce

1. Currently, the last seen data is only available via CSV on admin.atlassian.com.

Suggested Solution

Provide a REST API endpoint to retrieve the last seen per product.

Problem Definition

The existing endpoint Get users in an organization only provides data of managed accounts.

Workaround

Currently, only CSV is available for the use case.