list_repository_tag_history fallback orderby name

If tags are created at the same time (usually from a tight loop), it is
possible that they will be order nondeterministically unless we fallback
to another orderby.

data/model/tag.py

@@ -134,6 +134,7 @@ def list_repository_tag_history(repo_obj, page=1, size=100, specific_tag=None):
            .where(RepositoryTag.repository == repo_obj)
            .where(RepositoryTag.hidden == False)
            .order_by(RepositoryTag.lifetime_start_ts.desc())
+           .order_by(RepositoryTag.name)
            .paginate(page, size))
 
   if specific_tag: