[#418] netmap: Support NetmapService.NetmapSnapshot RPC

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

object/grpc/types.pb.go

@@ -1,7 +1,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.27.1
-// 	protoc        v3.21.5
+// 	protoc-gen-go v1.28.0
+// 	protoc        v3.21.6
 // source: object/grpc/types.proto
 
 package object
@@ -577,6 +577,13 @@ func (x *SplitInfo) GetLink() *grpc.ObjectID {
 //     Human-friendly name
 //   - FileName \
 //     File name to be associated with the object on saving
+//   - FilePath \
+//     Full path to be associated with the object on saving. Should start with a
+//     '/' and use '/' as a delimiting symbol. Trailing '/' should be
+//     interpreted as a virtual directory marker. If an object has conflicting
+//     FilePath and FileName, FilePath should have higher priority, because it
+//     is used to construct the directory tree. FilePath with trailing '/' and
+//     non-empty FileName attribute should not be used together.
 //   - Timestamp \
 //     User-defined local time of object creation in Unix Timestamp format
 //   - Content-Type \