Fetch comment details if given a comment permalink

[dgw]

It would be useful to show basic information like:

• Author (display name)
• When the comment was posted (absolute or relative, probably seconds_to_human())
• Comment score (like count)
• Reply count, if top-level
• Comment text up to the truncation limit for a single IRC line

Comment permalinks (obtained by right-clicking the timestamp on desktop YouTube; unsure if possible to obtain via mobile app) look like https://www.youtube.com/watch?v=[video_id]&lc=[comment_id]; the lc parameter is what we'll need to ask the YouTube Data API for more info about the comment/thread.

However the request is authorized (API key, OAuth), the API endpoint to get details of a specific comment is very simple, as I discovered by clicking around the YouTube API documentation for a few minutes and using the built-in "Try it" panel: https://youtube.googleapis.com/youtube/v3/comments?part=id%2Csnippet&id=Ugwh1UzoscaCmeYtNL14AaABAg

The equivalent for this plugin would be the comments resource's list() method, e.g. yt_client.comments().list('id,snippet', id=the_comment_id). Alternatively, the commentThreads resource gives better access to data such as whether the comment is a child (if it has a parentId, though replies' IDs often appear to have the format parent_ID.child_ID) and how many replies exist (totalReplyCount, which is always 0 for child comments as YouTube currently supports only one nesting level).