Data Export - Improve performance

[ChrisHuynh333]

What does this PR do and why?

This PR makes changes to the data export service and job to improve its performance for larger sample numbers.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other pull requests.

How to set up and validate locally

1. Test export with large number of samples
2. Ensure tests pass

PR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• [x] I have evaluated the PR acceptance checklist for this PR.

[github-actions[bot]]

Simplecov Report

Covered	Threshold
91.84%	90%