[Feature Request] - add OpenHome casting

[MRodneyMcKay]

Summary

Please, add support for audio casting to the app.

Description

Best case scenario would be, if the app was an openhome controller. It is similar to upnpav, but the main difference is that the owner of the playback que is the renderer, so if I close the android app, it would connect to the renderer and display the current playback.

Use Case

Casting is one of the best way to enjoy music on an AV system, and this is app is good enough for me to want to stay on it while listening to music on my amp. Openhome implementation would be to most convienent for the user and use less resources

Additional context