[Youtube] Added channel view count and subscriber count badges

[tarun7singh]

Added Channel view count and subscriber count badge.

• Moved Youtube base to youtube video base.
• Added Youtube channel subscriber badge
• Added Youtube channel total view count badge
• Added tests for both badges

Fixes #6111

[shields-ci]

	Warnings
⚠️	📚 Remember to ensure any changes to config.private in services/youtube/youtube-base.js are reflected in the server secrets documentation

	Messages
📖	✨ Thanks for your contribution to Shields, @tarun7singh!

Generated by 🚫 dangerJS against b05a458

[tarun7singh]

I had added another issue's code in this PR by mistake. Reverted it with a revert commit.

[PyvesB]

Thanks for the contribution @tarun7singh ! 👍🏻

The timing of this pull request is a bit unfortunate. I've just completed quite a tedious compliance process with the YouTube team (see #6276 for a bit more details). One of their conclusive notes is the following:

Please note that the quota extension has been granted ONLY for the use-case(s) mentioned in your quota extension request application and we may change your quota based on your actual quota usage as well as on your continued compliance with the YouTube API Services Terms of Service at any time.

Obviously I hadn't mentioned the new channel badges as they didn't yet exist at the time, but equally one could argue that it's an extension of the same use case. I suggest we move ahead with this, but one my review comments will be particularly important to address to make sure we don't break compliance.

[tarun7singh]

@PyvesB Completed all the requested changes.

[PyvesB]

@tarun7singh thanks for promptly addressing my review comments. Things mostly look good, though I think YouTubeBase can further be improved. Here's what I came up with after a bit of experimentation: 55ecd94

Note that https://www.youtube.com/video/SOME-ID redirects to https://www.youtube.com/watch?v=SOME-ID, which I've leveraged for consistency with https://www.youtube.com/channel/SOME-ID.

Let me know what you think and feel free to cherry-pick that commit back onto your PR branch. Otherwise, happy to approve as it is, I don't want to be too picky, so it's your call. 😉

[tarun7singh]

@PyvesB Yes your code looks much mor econcise but I was not able to successfully cherry pick this commit. can you please do it or tell me how to do it?

[PyvesB]

Try the following:

git remote add fork-pyvesb https://github.com/PyvesB/shields
git fetch fork-pyvesb
git cherry-pick 55ecd9416dce02da4b5f83fe2824c48c124d65bc

Alternatively, give me write permissions to your fork so that I can push the commit.

[tarun7singh]

@PyvesB Added your commit to the PR.

[PyvesB]

Thanks. Looks all good to me, let's get this merged! 👍