Implement a Kafka MQTT Publisher

Child of #656

Write a Kafka Consumer, which will consume messages from output-telemetry topic and post them to Tempus MQTT server as Telemetry Messages.

This consumer will post messages under a different device-id. It will maintain a mapping between source device and aggregated-device-id. This mapping will be temporarily stored in a Kafka topic.

The source tags will be modified to reflect the aggregation performed - for example AVG-Humidity-By-By for average Humidity. These tags will represent the aggregation function used, followed by original tag and parameters used for aggregation..

For aggregations performed over default window, no parameter is required - for example average Humidity over default window will be simply AVG-Humidity, whereas if aggregated by region, it will be named as AVG-Humidity-By-Region.