Bug 7407 - Add request leadership functionality to shards
This adds a new MakeLeaderLocal message to Shard class API.
MakeLeaderLocal message is sent to a local shard replica to request
the shard leader to be moved to the local node. Local shard will
contact the current leader with RequestLeadership message to initiate
leadeship transfer to itself. Original sender of MakeLeaderLocal
message will be notified about result of this operation.
Change-Id: I2b0ee7caf772457e31250d1bdddd5fc77b16fc53
Signed-off-by: Jakub Morvay <jmorvay@cisco.com>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>