Release 2.19.0 (#122)

* Add speaker diarization to streaming ASR clients (#116)

* enable speaker diarization for streaming_asr_client

* add: speaker diarization to transcribe_file

* fix: print confidence when word offsets are disabled

* Fix output format of transcribe_file.py client

* updates: add options to ASR and TTS clients (#118)

- Add/update list model option to ASR clients
- Add encoding option to TTS client

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Co-authored-by: Viraj Karandikar <16838694+virajkarandikar@users.noreply.github.com>