[Feat Request] Separate audio output for notification sounds

[kmoberg]

A feature that would be amazing to have in xpilot would be to be able to separate out Com1 and Com2 audio outputs, but also notification sounds like PMs, SELCAL, etc. That way you can specify these notifications to speakers but keep VOX in headset audio, allowing you to actually utilize the "Maintain SELCAL watch" ability.