improve playlist display aside

[ac615223s5]

Describe the feature

the playlist aside currently looks like this:

1. the videos should be numbered by their position.
2. there should be more than 2 items/videos visible at once without scrolling
3. there should be a link to the playlist's main page (/playlist?...)

Why would this be useful to add?

for a better sense of where the current (or another) video is within the playlist.

Concept(s)

on the youtube website:

Additional context

No response

Acknowledgements

• [X] I have searched the existing issues and this is NOT a duplicate or related to another open issue.
• [X] I have written a short but informative title.
• [X] I filled out all of the requested information in this form.