refactor(Playlist): Ignore ContinuationItem nodes from SectionList#contents (#579)

* feat(PlaylistVideo): Add `style`

* refactor(Playlist): Ignore `ContinuationItem` nodes in `SectionList#contents`

This should fix some issues regarding the library fetching the wrong continuation or empty continuations (NOTE: This means the solution in 987f506 no longer applies as empty continuations were all in `SectionList#contents`).

src/parser/classes/PlaylistVideo.ts

@@ -23,6 +23,7 @@ export default class PlaylistVideo extends YTNode {
   upcoming?: Date;
   video_info: Text;
   accessibility_label?: string;
+  style?: string;
 
   duration: {
     text: string;
@@ -44,6 +45,10 @@ export default class PlaylistVideo extends YTNode {
     this.video_info = new Text(data.videoInfo);
     this.accessibility_label = data.title.accessibility.accessibilityData.label;
 
+    if (Reflect.has(data, 'style')) {
+      this.style = data.style;
+    }
+
     const upcoming = data.upcomingEventData && Number(`${data.upcomingEventData.startTime}000`);
     if (upcoming) {
       this.upcoming = new Date(upcoming);