Improve Variant M3U8 Playlist Support

[zo-shin]

~The variant M3U8 playlist contains bandwidth attribute values. If it’s supported, there should be a bandwidth selection during playing. Currently the player can only play it without the bandwidth selection.~

[zo-shin]

I found the available streams are listed in information, and all of them are named as program 0. It’s better to give them different names based on the bandwidth or the resolution.