Vlad
I am not aware of extensions that do this. However, I am aware that Brave Browser on iOS has a similar ability to save videos offline to a playlist within the app itself.
Users can add videos to the browser's playlist to watch later by holding their finger on the video or adding it to the playlist with a button in the browser's ellipsis menu.
(Brave on iOS does not support choosing a specific resolution to save nor does it support editing segments of the video however).