Add local UDP discovery and invitation delivery for chat clients

lib/debug_config.c

@@ -137,6 +137,7 @@ static const struct {
     {"vad", DEBUG_CATEGORY_VAD},
     {"aec", DEBUG_CATEGORY_AEC},
     {"stream", DEBUG_CATEGORY_STREAM},
+    {"discovery", DEBUG_CATEGORY_DISCOVERY},
     {"all", DEBUG_CATEGORY_ALL},
     {NULL, DEBUG_CATEGORY_NONE}
 };