Investigate response format usage for different forms / processing workflows

## Description

Do some research around who is using HTML downloads.

> When thinking more about high volume responses, more possibilities might open up if we zoom out and assess who is using HTML downloads vs. CSV downloads vs. JSON downloads.

- Creating and downloading 1 CSV file VS. Thousands of HTML files can make quite a difference in terms of options we have.
- Could potentially consider other options for how we generate HTML from the JSON source files, after the fact?

Also look into: Are there any clear correlations with:
- volume of submissions?
- data processing downstream?
- form types?

## To investigate further

**We have an event:** This means we should be able to pull the data but we've had that event in place for 2yrs 8 months

`ga("download_format", {
formID,
downloadType,
numberOfRecords,
});`

Start with the existing ga("download_format", { formID, downloadType, numberOfRecords }) event, which the issue says has been available for 2 years and 8 months. Analyze HTML, CSV, and JSON download usage against submission volume, downstream processing, and form types. Done means documenting the observed correlations and implications for high-volume response generation.

Written by the indexing model from the issue text.