Add `bevy_audio_graph` RFC

[eira-fransham]

Rendered.

This RFC proposes a new system to handle audio, leveraging relationships and the ECS to define how audio is routed, and the Web Audio API (potentially implemented on desktop with the web-audio-api crate) to ensure high performance both natively and on the brower.

[rparrett]

Once a sound has been queued for playback, you lose control over it. You can stop the sound by deleting the AudioPlayer component, but there is no way to change the speed of playback, pause and resume, set a new location to play from, et cetera.

This section doesn't ring true: https://bevy.org/examples/audio/audio-control/

alternatives

The "better audio working group" is cooking up the following, under the same premise that abandoning rodio is the way forward.

https://github.com/corvusprudens/bevy_seedling https://github.com/BillyDM/firewheel

[eira-fransham]

@rparrett Thank you! I'm now switching my project to Seedling and in communication with the developer to start contributing.