MQTT protocol binding

[Alfusainey]

A container issue to implement the MQTT protocol binding for cloud events

[Alfusainey]

@slinkydeveloper @matzew How about starting this off by implementing the MQTT binding using the Eclipse Paho MQTT client library? The reason is that the spec distinguishes between the two mqtt protocol versions and having a client library that supports both MQTTv3 and MQTTv5 will be a good start.

My preference was to start with vertx-mqtt (its a popular library in IoT setups where scalability is important). However, it only supports MQTTv3. But there is an open issue to add MQTTv5 support and we can revisit once such support is added

[Alfusainey]

/assign

[slinkydeveloper]

@Alfusainey Feel free to go ahead with paho mqtt