Allow YouTube API v3 as alternative.

[kade-robertson]

I'd suggest allowing users to provide a YouTube Data API v3 key for obtaining metadata, it should be much quicker and allow for more compatibility. The only missing piece is a director picture but that's just about it.

Example request:

GET https://www.googleapis.com/youtube/v3/videos?part=snippet%2CcontentDetails%2Cstatistics&id=QASbw8_0meM&fields=items(contentDetails%2Fduration%2Csnippet(channelTitle%2Cdescription%2CpublishedAt%2Cthumbnails%2Fmaxres%2Ctitle))&key={YOUR_API_KEY}

This should provide the majority of data required and gets around age-gating issues.

{
 "items": [
  {
   "snippet": {
    "publishedAt": "2012-07-17T01:10:25.000Z",
    "title": "10 hour timer",
    "description": "10 hour timer (with 5 beeps at the end).\n➜ INSTAGRAM https://instagram.com/the16thcavern",
    "thumbnails": {
     "maxres": {
      "url": "https://i.ytimg.com/vi/QASbw8_0meM/maxresdefault.jpg",
      "width": 1280,
      "height": 720
     }
    },
    "channelTitle": "The 16th Cavern"
   },
   "contentDetails": {
    "duration": "PT10H5S"
   }
  }
 ]
}

[ZeroQI]

I did a YouTube movie and TV Series agent fork here: https://github.com/ZeroQI/YouTube-Agent.bundle
Use my absolute series scanner beta branch to go with it
YouTube Data API v3 is used