Add a contributors with active lists report

[TaiWilkin]

Overview

The exiting /admin/reports/countributors/ report shows all registered
accounts. We need a version that only lists those contributor accounts
that have submitted facilities.

This adds a contributors-with-active-facilities report.
It has the same output schema as the contributors report and
uses the same filter criteria as the /api/contributors endpoint.

Connects #988

Demo

Testing Instructions

• Checkout this branch
• Run vagrant ssh and ./scripts/server
• Open http://localhost:8081/admin/reports/contributors-with-active-facilities/
• You should see a report which contains the same contributors as the api/contributors endpoint, and takes the same format as the contributors report.

Checklist

• fixup! commits have been squashed
• CI passes after rebase
• CHANGELOG.md updated with summary of features or fixes, following Keep a Changelog guidelines

[jwalgran]

I ran the report, downloaded it, and compared it with the response from http://localhost:6543/api/contributors. Perfect match.