Refactored Kafka Application to simplify dependencies

1. Fixed a Bug in KafkaProducer. Without this fix the App will not send data in GPB format.
2. Added two new services - KafkaProducerService and KafkaConfigService.
3. Fixed a TODO in the register API to return Kafka server information.
4. Removed the use of LeadershipService and ClusterService, since we are not ready for clustering yet.

Change-Id: If20ef5238bb4629af0c6769129494eb44abf1d3c
diff --git a/apps/kafka-integration/core/pom.xml b/apps/kafka-integration/core/pom.xml
index 44df376..d29662d 100644
--- a/apps/kafka-integration/core/pom.xml
+++ b/apps/kafka-integration/core/pom.xml
@@ -30,7 +30,8 @@
     <packaging>bundle</packaging>
     <description>
         Kafka Integration Application.
-        This module is exclusive of REST calls and is only for the implementation of Apache Kafka.
+        This module is exclusive of REST calls and is only for the implementation
+        of the Application.
     </description>
 
     <dependencies>