libobs: Add audio to source profiler

[exeldro]

Description

Add audio to source profiler

Motivation and Context

As audio sources can have performance issues too add profiling of audio.
It provides the nanoseconds it takes to render audio per second.

How Has This Been Tested?

With changes to my source profiler plugin

Types of changes

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

Checklist:

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