[#220] blobstor: Implement "small" operations

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

pkg/local_object_storage/blobstor/delete_small.go

@@ -19,5 +19,5 @@ type DeleteSmallRes struct{}
 //
 // Returns ErrObjectNotFound if there is no object to delete.
 func (b *BlobStor) DeleteSmall(prm *DeleteSmallPrm) (*DeleteSmallRes, error) {
-	panic("implement me")
+	return b.blobovniczas.delete(prm)
 }