Magnum .opus

Adds .opus support to Minecraft's sound loader.

Opus is a modern audio codec that blows Ogg Vorbis out of the water for basically every use case, better quality, lower bitrates, smaller files. Ogg even admits it.

There's no good reason to still be shipping .ogg files if you care about audio quality. Yet here we are.

Magnum .opus patches the sound loader to handle .opus files natively, both streamed and static. Drop them in exactly like you would an .ogg and it works.

It also exposes an extensible API. Other mods can register support for their own custom audio formats with a single call, no mixins needed.