feat: add unavailable field for music tracks

fix: handling albums with unavailable tracks

tests/snapshots/youtube__music_album_show.snap

@@ -48,6 +48,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(1),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "Wqrg6ceVgK8",
@@ -73,6 +74,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(2),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "oWlZR0mU3fQ",
@@ -98,6 +100,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(3),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "pcdWTaNK_w4",
@@ -123,6 +126,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(4),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "hJhcL8A4AEI",
@@ -148,6 +152,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(5),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "ROwmS2PzXiE",
@@ -173,6 +178,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(6),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "u5fduXogSKU",
@@ -198,6 +204,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(7),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "37aeBkbW5Y4",
@@ -223,6 +230,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(8),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "Hn2701yNst0",
@@ -248,6 +256,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(9),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "dQiTv0BdwwA",
@@ -273,6 +282,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(10),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "DXYXlAljscM",
@@ -298,6 +308,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(11),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "mfbmff4MQ2M",
@@ -323,6 +334,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(12),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "mHkR5PHlHpQ",
@@ -348,6 +360,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(13),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "VBnKIZ1b5Cg",
@@ -373,6 +386,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(14),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "1iOIPRlLFgM",
@@ -398,6 +412,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(15),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "z1nDiIcnxoM",
@@ -423,6 +438,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(16),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "TNpe9wfbW9U",
@@ -448,6 +464,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(17),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "9FtXAfifarI",
@@ -473,6 +490,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(18),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "bRG8YR7ZBtI",
@@ -498,6 +516,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(19),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "wYV9GxkHdRE",
@@ -523,6 +542,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(20),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "wbrz2yUKiwo",
@@ -548,6 +568,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(21),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "_MUx8LqzuY8",
@@ -573,6 +594,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(22),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "s0xXo8ftgCA",
@@ -598,6 +620,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(23),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "6Q_etK9rgV8",
@@ -623,6 +646,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(24),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "4pwRZBhZH6Y",
@@ -648,6 +672,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(25),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "O75q5a1s02E",
@@ -673,6 +698,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(26),
       by_va: false,
+      unavailable: false,
     ),
     TrackItem(
       id: "KSD9dI_ZgPQ",
@@ -698,6 +724,7 @@ MusicAlbum(
       track_type: track,
       track_nr: Some(27),
       by_va: false,
+      unavailable: false,
     ),
   ],
   variants: [],