feat(extractors | providers): add subtitles(tracks) in some of the ex…

…tractors so that thumbnail preview can be used when progressing using slider, add sflix provider in movies and streamwish extractor in dramacool (#602)

dist/extractors/gogocdn.d.ts

@@ -1,10 +1,14 @@
-import { VideoExtractor, IVideo } from '../models';
+import { VideoExtractor, IVideo, ISubtitle } from '../models';
 declare class GogoCDN extends VideoExtractor {
     protected serverName: string;
     protected sources: IVideo[];
     private readonly keys;
     private referer;
-    extract: (videoUrl: URL) => Promise<IVideo[]>;
+    extract: (videoUrl: URL) => Promise<{
+        sources: IVideo[];
+    } & {
+        subtitles: ISubtitle[];
+    }>;
     private addSources;
     private generateEncryptedAjaxParams;
     private decryptAjaxData;

dist/extractors/streamwish.d.ts

@@ -1,7 +1,11 @@
-import { VideoExtractor, IVideo } from '../models';
+import { VideoExtractor, IVideo, ISubtitle } from '../models';
 declare class StreamWish extends VideoExtractor {
     protected serverName: string;
     protected sources: IVideo[];
-    extract: (videoUrl: URL) => Promise<IVideo[]>;
+    extract: (videoUrl: URL) => Promise<{
+        sources: IVideo[];
+    } & {
+        subtitles: ISubtitle[];
+    }>;
 }
 export default StreamWish;