[#1484] engine: Fix engine metrics

1. Add forgotten metrics for client requests
2. Include execIfNotBlocked into metrics

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

pkg/local_object_storage/engine/delete.go

@@ -58,6 +58,7 @@ func (e *StorageEngine) Delete(ctx context.Context, prm DeletePrm) (res DeleteRe
 			attribute.Bool("force_removal", prm.forceRemoval),
 		))
 	defer span.End()
+	defer elapsed("Delete", e.metrics.AddMethodDuration)()
 
 	err = e.execIfNotBlocked(func() error {
 		res, err = e.delete(ctx, prm)
@@ -68,8 +69,6 @@ func (e *StorageEngine) Delete(ctx context.Context, prm DeletePrm) (res DeleteRe
 }
 
 func (e *StorageEngine) delete(ctx context.Context, prm DeletePrm) (DeleteRes, error) {
-	defer elapsed("Delete", e.metrics.AddMethodDuration)()
-
 	var locked struct {
 		is bool
 	}