Get source upload

With this endpoint, you can inquire about the status of an upload job.

• If the value of the 'status' attribute is 'pending' or 'processing', you
  should check this endpoint again later.
• If the 'status' is 'failed', the content has failed to be uploaded to the
  resource.
• In case the upload job has been successful, you will receive a "303 - See
  Other" response and you can follow its Location header to see the
  list of strings
  that have been extracted from your file.