[extractor/common] improve Akamai HTTP format extraction
[extractor/common] improve Akamai HTTP format extraction

- Allow m3u8 manifest without an additional audio format
- Fix extraction for qualities starting with a number
Solution provided by @nixxo based on: https://stackoverflow.com/a/5984688

rg3/youtube-dl,Tatsh/youtube-dl,ozburo/youtube-dl,spvkgn/youtube-dl,ozburo/youtube-dl,rg3/youtube-dl,spvkgn/youtube-dl,Tatsh/youtube-dl