Add a client for getting data from YouTube

[jon-betts]

Requires:

• A simpler YouTube V1 model, without translation information #1107

Review notes

This PR uses an undocumented API for getting the JSON information. It seems the same data as the HTML scraping method, but avoids:

• Getting the JSON from the HTML
• Getting the HTML in the first place
• Dealing with cookie consent issues in the HTML

This is all being done a bit skin of the teeth. I'd ideally like to try more error scenarios, but I guess we'll catch them later.
The one I've spotted so far is that asking for a translated

Testing notes

You can play about as you'd like, but here is something to get you started.

from dataclasses import asdict
import json

from via.services.youtube_api import YouTubeAPIClient

client = YouTubeAPIClient()

# Get the video info
video = client.get_video_info("1v8u3ua6BPk")
print("Video details:")
print("\t", video.details.title)
print("\t", video.details.author)
print("\t", video.url)

# Try the matching system
caption_track = video.caption.tracks[0]
print("\nSelecting caption track:")
print("\t", caption_track)

# Get the transcript
transcript = client.get_transcript(caption_track)
print("\nTranscript:")
print(json.dumps(asdict(transcript), indent=4))

[seanh]

Labeling this as blocked just because it's waiting for me to get some more urgent PRs done before I can review this. I promise I'm working my way round to reviewing this ASAP!

[seanh]

Closing in favour of #1162