SERVER-14135 implement processHandshake() in LegacyReplicationCoordinator
SERVER-14135 implement getElectionId() in LegacyReplicationCoordinator
SERVER-14135 implement waitUpToOneSecondForOptimeChange() in LegacyReplicationCoordinator
SERVER-14135 implement shutdown() in LegacyReplicationCoordinator
SERVER-14135 implement buildsIndexes() in LegacyReplicationCoordinator
SERVER-14135 implement getHostsWrittenTo() in LegacyReplicationCoordinator