Add auto-reconnect functionality when disconnected

[longkerdandy]

Add the function of automatic reconnect when unexpectedly disconnected from the MQTT broker. Currently, there are two main difficulties:

1. The underlying MQTTNet library does not provide a robust auto-reconnect mechanism;
2. The reconnection of the Sparkplug client is not simply reconnecting to the MQTT broker, but also involves a series of operations to be performed.