Make "List Audio Devices", "List MIDI Devices", and "List Screens" fire events at start and when devices are added/removed

As of Vuo 1.2, these nodes fire events:

  • List Serial Devices
  • List Art-Net Devices
  • List OSC Devices
  • List Video Devices
  • List HIDs

…but these nodes don’t:

  • List Audio Devices
  • List MIDI Devices
  • List Screens

This feature request is to make the latter nodes fire events, for efficiency and consistency.

It probably does make sense for all of these device nodes to behave the same way.