Revert this file to previous version from FileHistory backup.
Finds the most recent FileHistory record with a backup for this file and restores the file from that backup. Before restoring, creates a new FileHistory record with change_type="revert" to backup the rejected content (flagged as approved). Updates the original FileHistory status to rejected (-1) and sets is_need_approval = true.
| Error |
if backup file doesn't exist or restore fails |