Python bindings to the libopus, IETF low-delay audio codec.

It allows python applications to use the Opus audio codec to encode
and decode audio, usually in order to reduce the network bandwidth
that is used by the application.

WWW: https://github.com/onbeep/opuslib

PR: 222038
Submitted by: Yuri Victorovich (maintainer)
Reviewed by: lifanov (mentor), matthew (mentor), koobs, sunpoet, mat
Approved by: lifanov (mentor), matthew (mentor), koobs
Differential Revision: https://reviews.freebsd.org/D12309