Change MQTT SDK to Paho

[jinfahua]

The plugin current is using fusesource MQTT SDK,

• The fusesource is not active.
• The MQTT 5.0 version was released at 2018, need support from MQTT SDK.

So we'll investigate the possibility to switch MQTT SDK to Paho

[frittentheke]

@jinfahua certainly Paho is the de-facto standard when it comes to MQTT and Java.
But please see this comment eclipse/paho.mqtt.java#570 (comment) about the outstanding bug fixes before jumping the gun here.

But since we are talking about the use case of doing performance measurements please take a look at MQTTBee (https://github.com/mqtt-bee/mqtt-bee) a new high performance MQTT library from the creators of the HiveMQ broker (https://www.hivemq.com/).

[jinfahua]

@frittentheke Thanks for your information, we will also take a look at the MQTTBee library. Thanks.