Data explorer CSV export

[jackfischer]

The query editor and CLI let you copy the resulting JSON which is nice but very common to use the data explorer for drilldown and straightforward CSV export would be a clear value add.

[scotttrinh]

We've talked about this one before, and I just wanted to note that CSV (probably TSV?) is a little tricky for non-table-like data. So we'd likely embed "interesting" data as JSON.

[jackfischer]

Makes sense. Leaving it out or outputting JSON blobs seems reasonable as a first pass.