message: fix url spelling
diff: Added an option to be able to trigger refreshes on entities based on a prestored arbitrary key.
  -The UrlReaderProcessor, FileReaderProcessor got updated to store the absolute url of the catalog file as a refresh key. In the format of `<type>:<target>`
  +The UrlReaderProcessor, FileReaderProcessor got updated to store the absolute URL of the catalog file as a refresh key. In the format of `<type>:<target>`
  The PlaceholderProcessor got updated to store the resolverValues as refreshKeys for the entities.
  