Speechmatics STT + multi-speaker conversations (#2036)

* initial config

* skeleton

* Added a README (to be added to).

* Payloads coming from the ASR.

* doc update

* handle the partials and finals

* enable diarization in the example

* support sending messages to pipecat pipeline

* requirements fix in README

* updated example (with amusement)

* updated example to match master

* updated docs

* support for diarization tags

* logic fix for wrapper

* Use an internal SpeechFrame for speaker_id (not user_id).

* only include speaker tags on finalised transcript (as this may skew end of utterance detection)

* updated docs

* correction to docs and updated example

* updated requirement

* Fix for using default EU server.

* Updates from PR comments.

* Refactor based on comments in the original PR.

Primary focus on documentation, naming conventions and how `user_id` is used.

* Check for SMX installed when importing.

* Variable name change

* Comment correction.

* Support for Esporanto and Uyghur

* Impoved language support

* function name change

* Locale fix

* intercept

* interim changes

* pass the pipeline task to the module for adding events to the top of the pipeline

* logging for the pipeline

* Reduce timeout for content aggregator.

* staged update

* testing with Azure

* Updated context (Azure was dropping punctuation) and using better ElevenLabs model.

* Updated to RT 0.3.0 and use OpenAI (not Azure).

* Missing OpenAI import; parameter name change for output locale validation.

* Revert to `0.2.0` of RT SDK.

* fix for assignment of `output_locale_code`.

* update Speechmatics library to 0.3.1

* new transcription example

* updated asyncio task handling

* Updated doc strings

* enable OpenTelemetry logging

* removed import from stt for __init__

* updated examples and default values

* updated examples

* prevent lock up when closing the STT connection

docs/api/requirements.txt

@@ -46,6 +46,7 @@ pipecat-ai[sambanova]
 pipecat-ai[silero]
 pipecat-ai[simli]
 pipecat-ai[soundfile]
+pipecat-ai[speechmatics]
 pipecat-ai[tavus]
 pipecat-ai[together]
 # pipecat-ai[ultravox] # Mocked