Simplify exports

[jeffm2001]

Description

This attempts to fix out-of-memory errors and timeouts when exporting larger (100-200k) campaigns. I have not tested it with really large campaigns.

What this PR does is simplify the collection of data in the export code. Previously, exportCampaign looped through all assignments in the campaign and then looped through each row in the assignment — potentially resulting in hundreds of thousands of queries for one export.

This changes it so that data is pulled with a few big queries (contacts, messages, question responses, tags), and does one loop through to combine/format the results in-place.

Checklist:

• I have manually tested my changes on desktop and mobile
• The test suite passes locally with my changes
• If my change is a UI change, I have attached a screenshot to the description section of this pull request
• My change is 300 lines of code or less, or has a documented reason in the description why it’s longer
• I have made any necessary changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• My PR is labeled [WIP] if it is in progress

[schuyler1d]

Bless you for this.

[schuyler1d]

This was successfully merged for Spoke 10.0