WiFi Sharing / Remote Playback improvements
This MR does the following:
- Fix playback of URLs sent to Apple TV using the web UI
- Fix automatic playback of the first file to reach 10% of received data on Apple TV
- Expose IPv6 option for WiFi sharing on tvOS as known from iOS
- Prefer IPv4 sockets over IPv6 sockets if there is choice (both on iOS and tvOS)