RFC 45-5: Allow selection of the audio codec/encoder

[tytan652]

Description

This PR is about the RFC 45.

Depends on:

• https://github.com/obsproject/obs-studio/pull/5104
• https://github.com/obsproject/obs-studio/pull/8087
• https://github.com/obsproject/obs-studio/pull/8088
• https://github.com/obsproject/obs-studio/pull/8089

Allow users to choose AAC or Opus to stream and record.

Stream side, codec are shown depending on the protocol used and the service compatibility.

If using different encoders in advanced, only common bitrates will be shown, this is made to avoid to over-complexify the UI.

Motivation and Context

Part of the implementation of the RFC 45.

How Has This Been Tested?

Only testing trying to stream SRT with opus and AAC, might need more testing.

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• [x] My code has been run through clang-format.
• [x] I have read the contributing document.
• [x] My code is not on the master branch.
• [x] The code has been tested.
• [x] All commit messages are properly formatted and commits squashed where appropriate.
• [x] I have included updates to all appropriate documentation.