Support both worker_version and worker_version_id in DetailsPanel

Closes #804 (closed)

This bug has the same root cause as #803 (closed) and has also been accidentally fixed by !1058 (merged). This MR just ensures that, should this kind of bug happen again, the frontend will still display a worker version because it will look for both the worker_version_id from ListElementChildren and the worker_version from RetrieveElement.