[Feature Request]: use YT thumbnail for trailer thumbnail

[Cas_]

Preflight checklist

• I have searched the issue tracker for a bug report that matches the one I want to file, without success.
• I have searched the features list for this feature, and I couldn't find it.
• I have checked that I'm using the latest stable version of the app.

Problem Description

currently trailer thumbnails are some anime thumbnails or cover images

Proposed Solution

consider using youtube thumbnails if they look good https://i.ytimg.com/vi/${id}/hqdefault.jpg

[Cas_]

it's not good as a default, but it's a passable fallback