Support for the new interface of Yandex.Music

I've updated the selectors for the new Yandex.Music interface.

Unfortunately I cannot check they are working because I've got this error when trying to install the extension to Chrome:

```
Failed to load extension from: /Development/chrome-media-keys/ext
Could not load '/Development/chrome-media-keys/ext/handler/npUnityControlPlugin.plugin' for plugin.
```