[#3] Added generate proto script create container method

Signed-off-by: Ilyas Niyazov <i.niyazov@yadro.com>

frostfs_sdk/models/mappers/placement_policy_mapper.py

@@ -0,0 +1,53 @@
+from typing import Optional
+
+from frostfs_sdk.models.mappers.filter_mapper import FilterMapper
+from frostfs_sdk.models.mappers.selector_mapper import SelectorMapper
+from frostfs_sdk.models.mappers.replica_mapper import ReplicaMapper
+from frostfs_sdk.models.dto.placement_policy import PlacementPolicy
+from frostfs_sdk.protos.models.netmap import types_pb2 as types_pb2_netmap
+
+
+class PlacementPolicyMapper:
+    @staticmethod
+    def to_grpc_message(policy: PlacementPolicy) -> Optional[types_pb2_netmap.PlacementPolicy]:
+        """
+        Converts PlacementPolicy DTO to gRPC message
+        
+        Args:
+            policy: PlacementPolicy DTO object
+            
+        Returns:
+            gRPC PlacementPolicy message
+        """
+        if not policy:
+            return None
+        
+        return types_pb2_netmap.PlacementPolicy(
+            unique=policy.unique,
+            container_backup_factor=policy.backup_factory,
+            filters=FilterMapper.to_grpc_messages(policy.filters),
+            selectors=SelectorMapper.to_grpc_messages(policy.selectors),
+            replicas=ReplicaMapper.to_grpc_messages(policy.replicas)
+        )
+
+    @staticmethod
+    def to_model(policy_grpc: types_pb2_netmap.PlacementPolicy) -> Optional[PlacementPolicy]:
+        """
+        Converts gRPC message to PlacementPolicy DTO
+        
+        Args:
+            policy_grpc: gRPC PlacementPolicy message
+            
+        Returns:
+            PlacementPolicy DTO object
+        """
+        if not policy_grpc or policy_grpc.ByteSize() == 0:
+            return None
+        
+        return PlacementPolicy(
+            replicas=ReplicaMapper.to_models(policy_grpc.replicas),
+            unique=policy_grpc.unique,
+            backup_factory=policy_grpc.container_backup_factor,
+            filters=FilterMapper.to_models(policy_grpc.filters),
+            selectors=SelectorMapper.to_models(policy_grpc.selectors)
+        )