Updating Snaps may cause websites to break

In a situation where a Snap updates to a new version, but certain websites don't support this version, the website could break.

- We can show a warning when the user updates the Snap.
- We can handle rolling back Snaps to the previous version (and keep state around of older Snaps versions).
- Potentially we just need to have documentation around how to handle breaking changes for Snaps developers.

This needs to be explored and thought about further.

No file, test, or entry point is named. Start by investigating how Snap updates and older versions are handled, then compare the proposed warning, rollback, and documentation approaches. Done requires choosing and scoping one approach for the compatibility problem.

Written by the indexing model from the issue text.