Add icon for AudioStreamInteractive

[Meorge]

This PR adds an icon for AudioStreamInteractive, based off the icons for the file-specific AudioStream types and AudioStreamPolyphonic:

The icon is a cog, representing the fact that there are logic or "mechanics" working behind the scenes of the stream. Hopefully it is readable enough as that at the target size; if not, we can work on adjusting it until it is more readable.