feat: get scan from cache

[imblue-dabadee]

Explanation

This introduces a new method for getting scan results from the cache directly. This will empower the extension to easily pull scan results and leverage the time-based caching logic that the controller has for the frontend.

Checklist

• [x] I've updated the test suite for new or updated code as appropriate
• [x] I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• [x] I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• [x] I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes