Add Speech Recognition v1p1beta1 samples

[beccasaurus]

This PR adds samples for Speech API's model selection feature.

Samples are based on Python canonical samples here: python-docs-samples#1361

• speech_transcribe_model_selection
• speech_transcribe_model_selection_gcs

Adds test resource samples/resources/Google_Gnome.wav which validates working video model

These samples are for API v1p1beta1. Samples & test are in separate files, following nodejs-vision convention: detect.v1p1beta1.js

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TODO

• Tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

[beccasaurus]

• repo-tools lint run complains about trailing commas
• npm run lint complains about missing trailing commas

Which linter are we using for samples? ESLint is angry.

[beccasaurus]

Ready to merge, pending review

[codecov]

Codecov Report

Merging #33 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master    #33   +/-   ##
=====================================
  Coverage     100%   100%           
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  Files           2      2           
  Lines          29     29           
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  Hits           29     29

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