refactor!: overhaul core classes and remove redundant code (#388)

* feat(Player.ts): append `cver` to deciphered URLs

* refactor(Actions.ts): remove redundant `getVideoInfo` function

This is leftover code from previous versions. It had many problems and it is no longer required.

* fix(Kids.ts): remove unneeded `await` keywords

* dev: add more endpoints

* chore: update deps

* refactor: separate endpoints into files

* dev: improve types

* dev: add more endpoints

* refactor: put clients in a separate directory inside `core`

* chore: lint

* refactor: move mixins and managers to separate folders

* chore: fix tests

* dev: add `CreateVideoEndpoint`

* chore: clean up

* chore: lint

* chore: add some comments

* chore: remove unnecessary test

* dev: add `playlist/CreateEndpoint`

* dev: add `playlist/DeleteEndpoint`

* dev: add `browse/EditPlaylistEndpoint`

* fix(parser): add a few checks to avoid parsing errors

src/parser/classes/analytics/AnalyticsVodCarouselCard.ts

@@ -17,7 +17,7 @@ export default class AnalyticsVodCarouselCard extends YTNode {
       this.no_data_message = data.noDataMessage;
     }
 
-    if (Reflect.has(data.videoCarouselData, 'videos')) {
+    if (Reflect.has(data, 'videoCarouselData') && Reflect.has(data.videoCarouselData, 'videos')) {
       this.videos = data.videoCarouselData.videos.map((video: RawNode) => new Video(video));
     }
   }