Improve performance for cache calls (#2749) & turn it on

[jwchumley]

What we're after:

The work to cache calls was completed but is not performant so we need to figure out why and improve performance and put it into production

Detailed documentation in #2749

• Research to resolve performance issue

[pkfec]

For cached calls, we observed that the requests are being cached before the request is completed. That added a big performance hit on the website. It looks like we no longer can use the after_request decorator.
Thinking of any alternatives like the celery worker could be feasible. Started some research work on how to use celery worker for caching the calls.

[pkfec]

To do's #

• Move the Cached_Calls to celery task
• Rewrite the after_request to create a celery task
• Review the documentation on how to set up celery on your local
  https://github.com/18F/openFEC/wiki/Slack-and-download-local-set-up

[pkfec]

@LindsayYoung : How do i configure the celery worker/beat to cache the requests in real time?

[pkfec]

Save and Retrieve Cache calls PR is merged to develop.
TODO :# Run the load test (locust) to make sure it doesn't impact the application performance and is working as expected in Dev and or in Stage once this change gets deployed.

[AmyKort]

I'm going to close this issue and make a new ticket for the load testing.