This patch introduces three new payloads which deal with replicating
local histories to followers. These are persisted whenever a transaction
chain (e.g. local history) is created or closed cleanly on the shard
leader. Followers can use these to track transaction chains and pick up
processing in case of a leader failover.
Change-Id: I3fe5ac153c88f23f9b871bd23cb04a8e2410af91
Signed-off-by: Robert Varga <rovarga@cisco.com>