Resolved links are not refreshed when target story changes slug

[didkan]

Found an issue with how resolve_links: 'url' in sync-stories.js works.
(from commit 946f8e3#diff-8bfd6da487a6a0275e22ffd0b774c74a)

When the story containing the link component (the link story) is published the url of the referenced target story (story to which the link points to) will be resolved and stored. The problem occurs when at a later time the slug of the target story is changed. At that time the stored link will "go stale" but there is no mechanism to trigger a new "resolve-links" call for the link story to update the stored url, resulting in broken links.

We need a way to identify all (link) objects that references the target story so that when it is published we can also mark them as stale or trigger a fetch/update for those objects.

[zimme]

Maybe we shouldn't use resolve link and resolve the links in our extension instead