Output level on Audio track do not show the slider names

[Trouffman]

Version 0.8.0

The name of the slider does not appear under the speaker icon.

This is "by design" (IIRC) as "audio track" volume cannot be changed, so the slider is for the monitoring only.

This end up confusing users between the audio tracks & input monitoring. (especially if using custom names for audio-tracks)

This would be similar to some feedback in #40