* Transcribe first cut: Medical: start, get and delete jobs.
* Added list_medical_transcription_job() support to Transcribe.
* Support for medical vocabularies.
* Added transcribe to list of backends to fix server mode error.
* PR3299 requested changes: don't offer deprecated decorator, regionalize download_uri, create/use service-specific exceptions.
Co-authored-by: Joseph Weitekamp <jweite@amazon.com>
