add will message on <device>/status topic, so status is always available even when offline.

add wifi/bssid topic to track which AP is connected
fix reconnect breaking out of loop

src/lib/mqtt.cpp

@@ -77,7 +77,7 @@ void mqttTask(void *pvParameters)
             {
                 // reconnect
                 if (!connectMqtt())
-                    return;
+                    continue;
             }
 
             if (hasLightLevel())