Google Cast support

Hello. It would be great to have ability to cast GetSound tracks via the Google Cast. It opens an access to playback on a lot of devices.

I suppose there are two options:

1. Playback to audio only device, such as Google Nest;

2. Playback to audio+video devices, such as Google Chromecast and lots of TVs which support it. In this case there might be an image and the same data as in the desktop app.