Issues in activating Kafka without mcast and IgmpProxy

Due to issues in activating onos-kafka without the mcast and IgmpProxy application we hade to revert dependency of Kafka on those apps
https://gerrit.opencord.org/#/c/18210/

Steps to replicate
1) bring up a clean VOLTHA+ONOS deployment
2) in ONOS cli app uninstall org.opencord.kafka
3) Build Kafka ONOS with mcast and igmpproxy changes (before https://gerrit.opencord.org/#/c/18210/)
4) mci inf the Kafka-onos folder
5) Try and install a new OAR with the with curl --fail -sSL --user onos:rocks -X POST -H Content-Type:application/octet-stream http://localhost:8181/onos/v1/applications?activate=true --data-binary @kafka-2.1.2-SNAPSHOT.oar
6) see error below

14:56:46.596 WARN [ApplicationManager] Unable to perform operation on application org.opencord.kafka
org.apache.felix.resolver.reason.ReasonException: Unable to resolve root: missing requirement [root] osgi.identity; osgi.identity=kafka; type=karaf.feature; version="[2.1.2.SNAPSHOT,2.1.2.SNAPSHOT]"; filter:="(&(osgi.identity=kafka)(type=karaf.feature)(version>=2.1.2.SNAPSHOT)(version<=2.1.2.SNAPSHOT))" [caused by: Unable to resolve kafka/2.1.2.SNAPSHOT: missing requirement [kafka/2.1.2.SNAPSHOT] osgi.identity; osgi.identity=org.opencord.mcast; type=osgi.bundle; version="[2.0.0.SNAPSHOT,2.0.0.SNAPSHOT]"; resolution:=mandatory [caused by: Unable to resolve org.opencord.mcast/2.0.0.SNAPSHOT: missing requirement [org.opencord.mcast/2.0.0.SNAPSHOT] osgi.wiring.package; filter:="(&(osgi.wiring.package=org.onosproject.mcast.api)(version>=2.2.0)(!(version>=3.0.0)))"]]
at org.apache.felix.resolver.Candidates$MissingRequirementError.toException(Candidates.java:1343) ~[?:?]
at org.apache.felix.resolver.ResolverImpl.doResolve(ResolverImpl.java:392) ~[?:?]
at org.apache.felix.resolver.ResolverImpl.resolve(ResolverImpl.java:378) ~[?:?]
at org.apache.felix.resolver.ResolverImpl.resolve(ResolverImpl.java:332) ~[?:?]
at org.apache.karaf.features.internal.region.SubsystemResolver.resolve(SubsystemResolver.java:257) ~[?:?]
at org.apache.karaf.features.internal.service.Deployer.deploy(Deployer.java:393) ~[?:?]
at org.apache.karaf.features.internal.service.FeaturesServiceImpl.doProvision(FeaturesServiceImpl.java:1062) ~[?:?]
at org.apache.karaf.features.internal.service.FeaturesServiceImpl.lambda$doProvisionInThread$13(FeaturesServiceImpl.java:998) ~[?:?]
at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
at java.lang.Thread.run(Thread.java:834) [?:?]
Caused by: org.apache.felix.resolver.reason.ReasonException: Unable to resolve kafka/2.1.2.SNAPSHOT: missing requirement [kafka/2.1.2.SNAPSHOT] osgi.identity; osgi.identity=org.opencord.mcast; type=osgi.bundle; version="[2.0.0.SNAPSHOT,2.0.0.SNAPSHOT]"; resolution:=mandatory [caused by: Unable to resolve org.opencord.mcast/2.0.0.SNAPSHOT: missing requirement [org.opencord.mcast/2.0.0.SNAPSHOT] osgi.wiring.package; filter:="(&(osgi.wiring.package=org.onosproject.mcast.api)(version>=2.2.0)(!(version>=3.0.0)))"]
at org.apache.felix.resolver.Candidates$MissingRequirementError.toException(Candidates.java:1343) ~[?:?]
... 12 more
Caused by: org.apache.felix.resolver.reason.ReasonException: Unable to resolve org.opencord.mcast/2.0.0.SNAPSHOT: missing requirement [org.opencord.mcast/2.0.0.SNAPSHOT] osgi.wiring.package; filter:="(&(osgi.wiring.package=org.onosproject.mcast.api)(version>=2.2.0)(!(version>=3.0.0)))"
at org.apache.felix.resolver.Candidates$MissingRequirementError.toException(Candidates.java:1343) ~[?:?]
at org.apache.felix.resolver.Candidates$MissingRequirementError.toException(Candidates.java:1343) ~[?:?]
... 12 more

To fix this please take a look at how the structure of the other apps are (with a difference between api package and implementation package) for example dhcpl2relay.
AN example of what has been done with the bng app:
https://gerrit.opencord.org/#/c/16652/
https://gerrit.opencord.org/#/c/17025/