Jetpack CRM: Fix hundreds of unneeded db queries (#40711)

* Add a cache to mitigate the problem.

* changelog

* Add line break at the end of the changelog file

* Update cache when making single settings requests

* Declare variable to satisfy static code analysis

* Force settings refresh from db

* Change self to static to allow dynamic resolution

* Refactor entire mitigation cache for issue 3504

* Change $key default value from 0 to false

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/12638546446

Upstream-Ref: Automattic/jetpack@7c21388

Author: tbradsha