opus: handle identification header.

[thinking-tower]

@pdeljanov, could you create another branch for Opus? The opus should be kept for reference for now.

Description

Part of the work for #8.

Porting over code from opus branch and verifying that it matches RFC 7845.

[pdeljanov]

Hey @thinking-tower, I made a new opus-dev branch for this work. I can delete the old opus branch once all the existing code is ported over to prevent any confusion.

[thinking-tower]

@pdeljanov Awesome, could you review this PR?

[pdeljanov]

Hi @thinking-tower, please see the review comment. Everything else looks okay to me.

[thinking-tower]

@pdeljanov I've changed the names of the test to be shorter than 100 characters, with longest being 62 characters long.

[pdeljanov]

Thanks, I've merged this now!

A suggestion for next time though: try not to rebase your PR branch and force push since it makes viewing changes impossible and removes the approval to run the CI automatically. I generally always squash PR branches into a single commit before merging so there's no need to worry about a messy history.

Cheers!