[web] add helper for getting file URL from history w/ filestore fallback GitOrigin-RevId: d77e6f1565fab407e1004a02c4bfdfe03a0214d7
[web] add helper for getting file URL from history w/ filestore fallback GitOrigin-RevId: d77e6f1565fab407e1004a02c4bfdfe03a0214d7