QPID-5800: [Java Broker] Refactor Derby/JDBC message store implementations to separate message and config store implementations.

* Message store implementations can now be used in isolation, which is useful when the user is using a JSON VirtualHostNode with
  another persistent store implementation.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1603626 13f79535-47bb-0310-9956-ffa450edef68
QPID-5800: [Java Broker] Refactor Derby/JDBC message store implementations - Address review comments from Alex Rudyy

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1603627 13f79535-47bb-0310-9956-ffa450edef68