HD channel art fetch for Channel overview page

[Feuerswut]

Checklist

• I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• I have read the contribution guidelines given at https://github.com/TeamNewPipe/NewPipe/blob/HEAD/.github/CONTRIBUTING.md.
• This issue contains only one feature request. I will open one issue for every feature I want to request.

What feature do you want?

This is a small fix/enhancement.
HD channel art fetch for Channel overview page. (YouTube extractor)

Why do you want this feature?

NewPipe currently extracts YouTube channel art at extremely low quality, the preview (on a channel preview page) looks pixelated.

NOTE: HD channel art seems to be fetched and shown in a search (using the search tool in the results) or in the comment section
-> everything there works properly.
This is NOT the case on the channel page (e.g. after clicking on a channel in the comments/search; look at the image in the upper right corner).

This can be fixed in the following way:

• Keep the current extreaction method.
• Try fetching the HQ image using either an existing method, or truncate the image url from this:

https://yt3.ggpht.com/ytc/AKedOLTU70U7Q6PAhn2C7Wght2Zi7ZZbQzBQHB-XXXXXXX=s100-c-k-c0x00ffffff-no-rj

to this

https://yt3.ggpht.com/ytc/AKedOLTU70U7Q6PAhn2C7Wght2Zi7ZZbQzBQHB-XXXXXXX

provided that you have the url
(e.g. truncate anything after the '=' char.)
Note: example url, NOT functional

A plain browser displays the 2nd url-image without issue.

[ghost]

Any updates to this?