Clustering : Use Normalized Node streaming code when persisting snapshots and replicating snapshots

Use NormalizedNode stream writer when,
1. Persisting a snapshot

• The transaction that reads the data from the store should not serialize the NormalizedNode
• CaptureSnapshotReply should pass the read NormalizedNode to the RaftActor wrapped by a Serializable. This will keep the interface generic.
• To reduce memory issue the captured snapshot will not be stored in memory

2. Install snapshot

• Change message to java serializable and rely on akka to write the serializable to the stream
• When a snapshot needs to be installed the snapshot needs to be created.