Aggregate views (7542, 7622)

This fixes [#7542](https://issues.dp.la/issues/7542) and [#7622](https://issues.dp.la/issues/7622).  It syncs the QA app with the new global reports in the ingestion code.  It also dynamically calculates CouchDB view counts.  

See [#7542](https://issues.dp.la/issues/7542), notes 19-22.
Add a comment about why `options[:group_level]` must be 2.