Add source option to prevent usage of HLS native implementation

[marcosbozza]

This PR adds a new optional boolean option called overrideNative to a stream source to prevent the use of some browser's native HLS capabilities. This forces the use of Media Source Extensions to provide a more consistent experience between browsers.

The use case where we encountered problems with HLS was on Safari when trying to modify the XHR requests. Since it is native on Safari, it is not a XHR request, making it impossible to modify the requests.

Example of usage:

sources: [
    {
        type: 'hls',
        file: 'https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8',
        overrideNative: true,
    }
]

This options was inspired by the options with same name in HLS plugin for VideoJS
https://github.com/videojs/http-streaming#overridenative

This is our first PR to contribute to OvenPlayer. We had a good experience using it so far and we are glad to be able to contribute. Please let us know if this new options makes sense and any changes we might have to address.

[SangwonOh]

Thanks for quick response!

[dygy]

@marcosbozza hi, have you tested a new code?
i've installed ovenplayer like this
"ovenplayer": "git://github.com/AirenSoft/OvenPlayer.git#1e4a3d396ba59abb359aa867c00b782b84747811",
i've made config like this
type: "hls", file: url, overrideNative: true, sectionStart: 3,
in fact, i've seen native implementation and none of op_hls were created. :(