Cleanup Covid Pipeline code and infra

[DanielSass]

Description

#8935 Describes the minimum necessary work to stop sending things to the covid pipeline. This ticket is meant to encapsulate the remaining work to completely remove the covid pipeline.

ReportStream has finished their "shadow migration" of receivers off of the covid pipeline (link). We can now remove the CSV submissions and associated infrastructure.

This includes

• [x] Bulk upload CSV logic, submission and response storage
• [x] Backend creating a CSV message via the TestEventExport class and putting it on the queue
• [ ] Infrastructure for the CSV message (queue + function app)
• [x] Any alerts associated with covid submissions (at least one for the function app + queue, possibly more)
• [ ] Modify/remove any tests as needed

Proposed solution

Remove queue and function app infrastructure.

Additional context

Add any other context about the feature, alternatives considered, link to Figma, etc.

[DavidMcClatchey]

Feel free to delete TestEventExport class as well. Double check it's not being used.