[Feature] Add header attributes support

[freearhey]

Sometimes in extended m3u playlists, additional attributes are used right in the header. For example:

#EXTM3U x-tvg-url="http://example.com/epg.xml.gz"

Could you please add support for such attributes?

[NimitzDEV]

Seems like it won't be hard to support, will support this feature in the coming days. (National holidays here days ago, so didn't answer your post in time sorry for that)