support itunes urls

[monkeydom]

Metalove.get_podcast/1 should also accept and resolve itunes links. e.g.

https://itunes.apple.com/us/podcast/elixirtalk/id1298287048?mt=2

by resolving it using
https://itunes.apple.com/lookup?id=1298287048&entity=podcast

and then looking for feedURL in the results.

{
   "resultCount" : 1,
   "results" : [
      {
         "feedUrl" : "http://feeds.soundcloud.com/users/soundcloud:users:334579745/sounds.rss",
         "wrapperType" : "track",
         "trackPrice" : 0,
         "collectionCensoredName" : "Elixir Talk",
         "country" : "USA",
         "trackCensoredName" : "Elixir Talk",
         "artworkUrl100" : "https://is2-ssl.mzstatic.com/image/thumb/Music123/v4/7e/1b/5d/7e1b5d27-861b-822e-9495-aa1fe75692eb/source/100x100bb.jpg",
         "collectionName" : "Elixir Talk",
         "collectionViewUrl" : "https://podcasts.apple.com/us/podcast/elixir-talk/id1298287048?uo=4",
         "collectionPrice" : 0,
         "releaseDate" : "2019-07-12T00:19:00Z",
         "artworkUrl30" : "https://is2-ssl.mzstatic.com/image/thumb/Music123/v4/7e/1b/5d/7e1b5d27-861b-822e-9495-aa1fe75692eb/source/30x30bb.jpg",
         "collectionExplicitness" : "cleaned",
         "primaryGenreName" : "Technology",
         "genres" : [
            "Technology",
            "Podcasts"
         ],
         "kind" : "podcast",
         "trackHdPrice" : 0,
         "trackExplicitness" : "cleaned",
         "collectionHdPrice" : 0,
         "contentAdvisoryRating" : "Clean",
         "trackHdRentalPrice" : 0,
         "currency" : "USD",
         "trackViewUrl" : "https://podcasts.apple.com/us/podcast/elixir-talk/id1298287048?uo=4",
         "genreIds" : [
            "1318",
            "26"
         ],
         "trackName" : "Elixir Talk",
         "artworkUrl60" : "https://is2-ssl.mzstatic.com/image/thumb/Music123/v4/7e/1b/5d/7e1b5d27-861b-822e-9495-aa1fe75692eb/source/60x60bb.jpg",
         "trackId" : 1298287048,
         "trackCount" : 48,
         "artworkUrl600" : "https://is2-ssl.mzstatic.com/image/thumb/Music123/v4/7e/1b/5d/7e1b5d27-861b-822e-9495-aa1fe75692eb/source/600x600bb.jpg",
         "artistName" : "Elixir Talk",
         "trackRentalPrice" : 0,
         "collectionId" : 1298287048
      }
   ]
}