Bug 4105: Added DistributedEntityOwnershipService and wiring

Bug 4105: Added DistributedEntityOwnershipService and wiring

Added a skeleton DistributedEntityOwnershipService impl class and config
system wiring.

I initially tried to instantiate it in the operational store module but
it needs to be its own service and AFAIK you can only provide one
service per module as createInstance returns a single AutoCloseable.

So I created a new config yang and xml for distributed-entity-ownership-service.
We also need a separate config yang service identity to allow for
multiple impls - I put this in sal-common-api where the
EntityOwnershipService is defined.

Change-Id: I4883af2e749bca5c9dfdac69cf943017294435a3
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>