chore: mqtt impl, fix more wiznet bugs

.vscode/settings.json

@@ -18,6 +18,13 @@
         "systick.h": "c",
         "timer.h": "c",
         "stdint.h": "c",
-        "mqtt_interface.h": "c"
+        "mqtt_interface.h": "c",
+        "gpio.h": "c",
+        "modbus_handler.h": "c",
+        "rs485.h": "c",
+        "system_init.h": "c",
+        "mqtt_handler.h": "c",
+        "cstdlib": "c",
+        "modbus_master.h": "c"
     }
 }