[FEAT] Implement Feeding Audio File to Streaming/Live API for CI/CD

[dvonthenen]

Proposed changes

This implements feeding a WAV file (currently only supports WAV) into the Streaming/Live API websocket. This is to create reproducible transcription for a CI for a "live" conversation. Since the live conversation is a recording, the results of the transcription should be 100% reproducible.

In implementing this feature, I found a gap in the Metadata message returned in the Live API. This also implements the Metadata message and callback in the interface. Also, cleans up some logging to the user that should not be needed.

Types of changes

What types of changes does your code introduce to the community Go SDK?
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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update or tests (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Further comments

This is mainly meant for CI/CD and not for general use.