fix(FEV-1291): clear thumbnail manager for Youtube entries in playlis…

…t and export engineType to be used by plugins (#555)

clear thumbnail manager for Youtube entries in playlist and export engineType to be used by plugins

solves: FEC-12369

src/kaltura-player.js

@@ -169,6 +169,8 @@ class KalturaPlayer extends FakeEventTarget {
     this.configure({session: mediaConfig.session});
     if (!hasYoutubeSource(sources)) {
       this._thumbnailManager = new ThumbnailManager(this, this.config.ui, mediaConfig);
+    } else {
+      this._thumbnailManager = null;
     }
     addKalturaPoster(sources, mediaConfig.sources, this._localPlayer.dimensions, this.shouldAddKs() ? mediaConfig.session?.ks : '');
     addKalturaParams(this, {...playerConfig, sources});

ts-typed/player.d.ts

@@ -40,6 +40,7 @@ declare namespace KalturaPlayerTypes {
     ui: any;
     config: KalturaPlayerTypes.PlayerConfig;
     provider: any;
+    engineType: string;
     cuePointManager: KalturaPlayerTypes.CuePointManager;
     ready: () => Promise<any>;
     sources: KalturaPlayerTypes.Sources;