Closes #8075
Fixes #6046
The youtube extractor was using 'mp4' for them, therefore filters like 'bestaudio[ext=m4a]' stopped working (94278f7202 broke it).
94278f7202
Currently only email login supported
RSS used instead of manifest files because it's exact to the millisecond with the video I tested while in manifest it's only exact to the second.
Fix view count parsing when the decimal marker is a whitespace, e.g. '101 101'