[#1449] tree: Add ApplyBatch method

Concurrent Apply can lead to child node applies before parent, so
undo/redo operations will perform. This leads to performance degradation
in case of tree with many sublevels.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/services/tree/replicator.go

@@ -40,6 +40,7 @@ const (
 	defaultReplicatorCapacity    = 64
 	defaultReplicatorWorkerCount = 64
 	defaultReplicatorSendTimeout = time.Second * 5
+	defaultSyncBatchSize         = 1000
 )
 
 func (s *Service) localReplicationWorker(ctx context.Context) {