Added metadata refresh capability immediately after subtitle generation
when handling Plex webhooks. If subtitle generation is successful, the
Plex item's metadata is attempted to be refreshed to ensure that the
updates are reflected. The change includes robust error handling to log
failures in refreshing metadata and alerts the user if the webhook is
misconfigured. This enhancement improves the overall user experience by
ensuring the media library is up-to-date after any subtitle changes.
113e0a203c