feature: background job cache invalidation

[Jan-Jasek]

Motivation

Implements background worker to periodically invalidate cache using change feed output

Checklist

• [x] Code follows coding conventions held in this repo
• [ ] Automated tests have been added
• [x] Tests are passing
• [x] Docs have been updated (if applicable)
• [x] Temporary settings (e.g. variables used during development and testing) have been reverted to defaults