Address instability from report download caching

[ecayer]

In order to improve report performance, the team initially implemented a cache, but this isn't working. We are going to replace the cache with an approach that separates out report generation from downloading in the UI.

For more details on the problem and proposed approach, see here the ADR to Improve API stability when processing job data and generating reports

A full fix for this includes the following fixes and improvements and investigations:

• [ ] https://github.com/GSA/notifications-api/issues/1395
• [ ] https://github.com/GSA/notifications-api/issues/1393
• [ ] https://github.com/GSA/notifications-api/issues/1391
• [ ] https://github.com/GSA/notifications-api/issues/1390

[ecayer]

@ccostino Do you have a preference whether we group the work to decouple report generation/download with this or track it in a separate epic? And there isn't yet an issue that includes the UI for that, right?