Support AV1 / HEVC via RTMP

[clone1018]

The OBS Project recently added support for the Enhanced RTMP v1 spec, which allows for additional codec negotiation.

Since Waveguide is (or will be) codec agnostic, we should be able to support these standards as well. However I'm not sure there's a great Go library that has support for this "new spec" so that may be required before moving forward.

[clone1018]

Worth mentioning we already maintain a go-rtmp fork.

[nassah221]

I think the main issue with supporting av1 would be the decoding of stream for the thumbnailer.