feat(YouTube): Add Alternative thumbnails patch

[LisoUseInAIKyrios]

Added the option to replace video thumbnails using YouTube provided thumbnails of in video images. This provides functionality similar to the Chrome Clickbait Remover extension, but this does not alter video titles.

For example, the video:
https://www.youtube.com/watch?v=PSrO55KS6VY
Normally uses this as it's thumbnail:
https://i.ytimg.com/vi/PSrO55KS6VY/hq720.jpg

But with this patch, you can select from using a video still from the beginning:
https://i.ytimg.com/vi/PSrO55KS6VY/hq720_1.jpg
Middle:
https://i.ytimg.com/vi/PSrO55KS6VY/hq720_2.jpg
Or end of the video:
https://i.ytimg.com/vi/PSrO55KS6VY/hq720_3.jpg

Normal (patch off):

Alt thumbnails (patch on):

Because these alt images do not exist for all videos, the patch must first check if the alt image exists before using it. Depending on the internet connection, this usually adds between 20ms to 200ms of delay.

An additional option for "fast alt images" exists, where it always uses SD (medium quality) images, and skips the verification step. This means the alt images load at the same speed or faster than the original. But because the alt image may not exist for some videos (particularly, live streams, unreleased upcoming videos, and some very old videos), the thumbnails will show up as blank because the alt image does not exist. For these blank thumbnails, if they are dragged off and then on screen again, then the original thumbnail is loaded instead. It must use SD image quality (and not the higher HQ720) because HQ720 does not exist for many videos and too many thumbnails will initially fail to load.

This fast alt images feature is only intended for users with very slow internet connections and they are willing to accept a few blank live stream thumbnails in exchange for faster thumbnail loading. I considered removing this option for simplicity, but left it in after trying it on a super slow public wifi connection and found it useful.

This PR started as integration of both DeArrow and alt images, but I decided to move DeArrow into it's own patch after the alt thumbnails code grew in size and complexity. DeArrow will come as a separate PR in the future where DeArrow can be used as the preferred thumbnail (use whenever possible), and if DeArrow is not available then show the alt or the original thumbnail.

Integration changes

[oSumAtrIX]

The patch is under the dearrow package, even though, as of now, there is no relation to DeArrow. Is this intended? (I know about the separation of DeArrow integration). "Alternate" has a different meaning from "Alternative", please rename all references.

[YT-Advanced]

Wait, since DeArrow have their function to generate thumbnail at certain time, so hope @ajayyy can add it so we can solved thumbnail issues

[LisoUseInAIKyrios]

Wait, since DeArrow have their function to generate thumbnail at certain time, so hope @ajayyy can add it so we can solved thumbnail issues

I had both DeArrow and alt images working together (you can see the initial attempt in the prior commits of this PR). But decided to make DeArrow its own patch in a separate future PR.

[YT-Advanced]

Wait, since DeArrow have their function to generate thumbnail at certain time, so hope @ajayyy can add it so we can solved thumbnail issues

I had both DeArrow and alt images working together (you can see the initial attempt in the prior commits of this PR). But decided to make DeArrow its own patch in a separate future PR.

No, I mean seekbar thumbnail 😥