Upstream commits that have not been merged

• [jsinterp] Improve parsing
  • The changes appear to be pointless?
• [ITV] Overhaul ITV extractor
  • Need help!
  • related ITV-X #5570
• [feat] Add support to external downloader aria2p
  • We partially have a different implementation, but is broken. Need to fix it
  • No need to use aria2p, we can achieve same with websockets directly
• [fd/dash] range for mpd fragments
  • Related: [ie/common] Support ranges in MPD #8711
• [ie] range for mpd
  • Related: [ie/common] Support ranges in MPD #8711
• [ie] Correctly resolve base-url in manifest
  • Related: yt-dlp fails to parse MPD manifest: KeyError('sourceURL') #8269
• [utils] base for int_or_none
• [fd/external] Rework ffmpeg detection
• [test:download] Support playlist_maxcount expected value