Bug 2187: Implement add-replicas-for-all-shards RPC

Bug 2187: Implement add-replicas-for-all-shards RPC

Implemented the add-replicas-for-all-shards RPC. The yang RPC definition
was changed to return a list of results for each shard.

In the unit test I added a shard config dynamically to the new replica
member that doesn't exist in the leader to test a replica failure case.
This revealed an issue for FindPrimary where both member nodes forwarded the
RemoteFindPrimary message back and forth to each other as neither had
a local replica. To fix this, I added a visitedAddresses set to the
RemoteFindPrimary message to prevent the endless mutual recursion.

Change-Id: Icb0329db2c935f9825b81f593b83bdab13fa6b52
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>