Add basic control options for audio input streams

[badaix]

As documented here

• Play: Start playback
  • params: none
• Pause: Stop playback
  • params: none
• PlayPause: Toggle play/pause
  • params: none
• Stop: Stop playback
  • params: none
• Next: Skip to next track
  • params: none
• Previous: Skip to previous track
  • params: none
• Seek: Seek forward or backward in the current track
  • params:
    • Offset: [float] seek offset in seconds
• SetPosition: Set the current track position in seconds
  • params:
    • Position: [float] the new track position