[DEV-15635] Update download regex and add test case

[sethstoudenmier]

Description:

Fix some of the download columns swapping their values due to similar names between the generated CSVs and the database columns.

Technical Details:

Django changed how the queryset queries are represented which broke the regex that is used to determine which columns are a direct select vs annotations. This PR updates that regex, removes some checks that were previously added, and then adds a test case to hopefully catch any future potential changes.

A decent amount of the changes came from running ruff format on the file.

Requirements for PR Merge:

1. Unit & integration tests updated
2. API documentation updated (examples listed below)
   1. API Contracts
   2. API UI
   3. Comments
3. Data validation completed (examples listed below)
   1. Does this work well with the current frontend? Or is the frontend aware of a needed change?
   2. Is performance impacted in the changes (e.g., API, pipeline, downloads, etc.)?
   3. Is the expected data returned with the expected format?
4. N/A Appropriate Operations ticket(s) created
5. Jira Ticket(s)
   1. DEV-15635

Explain N/A in above checklist:

[james-at-kc]

LGTM