[CPP] Cleanup data structure of PublicationManager
[CPP] Cleanup data structure of PublicationManager

* when removing broadcast, the metadata stored in the internal data
  structure of the PublicationManager shall be cleaned up

Change-Id: Ib070364b5ce921893ab5ab10039901700fd4acbf

bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr,clive-jevons/joynr,bmwcarit/joynr