Implement In-Device Audio

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Audio is currently generated on the server and streamed to the devices. This reduces the complexity of client side code, but results in a host of issues including delays to due buffering or network latency, audio cut offs due to wifi or mobile data connections, and more. We should use standard game audio handling libraries to play the audio tracks.

Implementing this fuctionality requires work in all four codebases (Server Python, Web JavaScript, iOS and Android) This can be used as the primary Android issue, but sub-issues should be created for the specific features required.