master
splitted `operation.List` to five list operations `operation.List{BuildIndex,ImportFromS3,ExportToS3,ExportToYT,ExecuteQuery}`
* Added operation service client through `db.Operation()` method (supports methods `Get`, `List`, `Cancel` and `Forget`)
added test for describe node
initial read messages within transaction
Enabled containedctx linter
* Fixed bug with fail cast of grpc response to `operation.{Response,Status}`
refactoring: move internal/xerrors.operationStatus to internal/operation/status.Status
enabled nlreturn (#1027)