Invidious does not currently support non-livestream hls playback
Originally, the HLS manifest check was essentially a boolean:
if the HLS manifest field was present, it was assumed to be a
livestream. Some videos include the HLS Manifest but aren't
livestreams.
In the case where they are livestreams, the video contains a videoType
field with the value "Livestream". In the case that they're normal
videos, the videoType is "Video". This is exposed via the
`video.live_now` property.
This commit just checks that `video.live_now` is true before treating
it as a livestream
fe4fa0480a