MQTT: WIP fix modified status not being set when adding and modifying topics or attributes.

Fix loading of CSV that was not applying model types, and that not checking conformance either.

<?xml version='1.0' encoding='utf-8'?>
<ModbusServerNode xmlns:xsd="http://www.w3.org/2001/XMLSchema" Local_Port_Number="1502" Local_IP_Address="127.0.0.1"/>