Implement UDP multicast handler start/stop to ensure proper lifecycle (#9524)

* Implement UDP multicast handler start/stop to ensure proper lifecycle

* Add close method to AsyncUDP and improve UDP multicast handler lifecycle management

* Guard portduino

src/mesh/wifi/WiFiAPClient.cpp

@@ -391,6 +391,11 @@ static void WiFiEvent(WiFiEvent_t event)
         LOG_INFO("Disconnected from WiFi access point");
 #ifdef WIFI_LED
         digitalWrite(WIFI_LED, LOW);
+#endif
+#if HAS_UDP_MULTICAST
+        if (udpHandler) {
+            udpHandler->stop();
+        }
 #endif
         if (!isReconnecting) {
             WiFi.disconnect(false, true);
@@ -417,6 +422,11 @@ static void WiFiEvent(WiFiEvent_t event)
         break;
     case ARDUINO_EVENT_WIFI_STA_LOST_IP:
         LOG_INFO("Lost IP address and IP address is reset to 0");
+#if HAS_UDP_MULTICAST
+        if (udpHandler) {
+            udpHandler->stop();
+        }
+#endif
         if (!isReconnecting) {
             WiFi.disconnect(false, true);
             syslog.disable();