[#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>

config/example/node.env

@@ -31,6 +31,7 @@ FROSTFS_TREE_REPLICATION_CHANNEL_CAPACITY=32
 FROSTFS_TREE_REPLICATION_WORKER_COUNT=32
 FROSTFS_TREE_REPLICATION_TIMEOUT=5s
 FROSTFS_TREE_SYNC_INTERVAL=1h
+FROSTFS_TREE_SYNC_BATCH_SIZE=2000
 FROSTFS_TREE_AUTHORIZED_KEYS="0397d207ea77909f7d66fa6f36d08daae22ace672be7ea4f53513484dde8a142a0 02053819235c20d784132deba10bb3061629e3a5c819a039ef091841d9d35dad56"
 
 # gRPC section

config/example/node.json

@@ -69,6 +69,7 @@
     "replication_worker_count": 32,
     "replication_timeout": "5s",
     "sync_interval": "1h",
+    "sync_batch_size": 2000,
     "authorized_keys": [
       "0397d207ea77909f7d66fa6f36d08daae22ace672be7ea4f53513484dde8a142a0",
       "02053819235c20d784132deba10bb3061629e3a5c819a039ef091841d9d35dad56"

config/example/node.yaml

@@ -59,6 +59,7 @@ tree:
   replication_channel_capacity: 32
   replication_timeout: 5s
   sync_interval: 1h
+  sync_batch_size: 2000
   authorized_keys:  # list of hex-encoded public keys that have rights to use the Tree Service with frostfs-cli
     - 0397d207ea77909f7d66fa6f36d08daae22ace672be7ea4f53513484dde8a142a0
     - 02053819235c20d784132deba10bb3061629e3a5c819a039ef091841d9d35dad56