BUG-5685: Register BGP Application Peer Cluster Singleton Service

BUG-5685: Register BGP Application Peer Cluster Singleton Service

Register BGP Application Peer Cluster Singleton Service.
When running on clustering, it was need it to have different
configuration per instance to avoid conflicts.
Now all instance can have same configuration,
since cluster service provider take cares of make active
the one is running on Leader Cluster. If Leader goes down,
the instance from the new Leader will become active.

Change-Id: I5316a50b5ceaf54c838018860baefc5ae326465b
Signed-off-by: Claudio D. Gasparini <cgaspari@cisco.com>