plugin.api.useragents: update User-Agent's
plugin.api.useragents: update User-Agent's

- update all User-Agent's
- use newer User-Agent's for some duplicates,
  for backwards compatibility they are not removed

streamlink/streamlink,streamlink/streamlink,melmorabity/streamlink,bastimeyer/streamlink,chhe/streamlink,melmorabity/streamlink,chhe/streamlink,bastimeyer/streamlink,gravyboat/streamlink,gravyboat/streamlink