fix vertical audio exclusion

[summeroff]

Description

Fix processing of audio for global sources what does not have scene item to control if they should go to specific output.
Include small code cleanup and debug log removal.

Motivation and Context

Global audio sources does not processed in same way as scene items. And was missing from initial implementation.

How Has This Been Tested?

Test builds of libobs/osn was made to test if sound goes to all destinations.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the streamlabs 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.

[mhoyer-streamlabs]

Looks good.