Fixed HLS streams. Calling NRK API with user_agent based on Client.Platform

Used same procedure as SVTPlay:
https://github.com/plexinc-plugins/Services.bundle/blob/0feaf536f47800cf4689452bfb09c10c2b2732d3/Contents/Service%20Sets/com.plexapp.plugins.svtplay/URL/SVTPlay/ServiceCode.pys.

Reading m3u8 to get correct streams.