Rename `upload_*_to_s3` to no longer reference s3

TNL-534
Add coverage for cohort view's `showSection` link

TNL-550
Create standard way of updating a task's progress

TNL-566
Bump the report downloads poll interval to 20 seconds

TNL-565
Merge pull request #5528 from edx/dan-f/data-download-tech-debt

Student profile CSV background task tech debt