mac-capture: Add several virtual audio drivers to Desktop audio

This allows the following virtual audio devices to be listed as Desktop Audio devices:
- loopback;
- iShowU;
- BlackHole.

plugins/mac-capture/audio-device-enum.c

@@ -11,7 +11,10 @@ static inline bool device_is_input(char *device)
 {
 	return astrstri(device, "soundflower") == NULL &&
 	       astrstri(device, "wavtap") == NULL &&
-	       astrstri(device, "soundsiphon") == NULL;
+	       astrstri(device, "soundsiphon") == NULL &&
+	       astrstri(device, "ishowu") == NULL &&
+	       astrstri(device, "blackhole") == NULL &&
+	       astrstri(device, "loopback") == NULL;
 }
 
 static inline bool enum_success(OSStatus stat, const char *msg)