Split off from OC-16.
Currently we write out empty provenance values in the file if none are configured in the tool. It's not obvious to a new user that they need to open the provenance editor and set those values, so we should prompt them to fill it out on startup if no values are set.
(Optional: only prompt them the first time the app is run.)
(Also optional: don't write out provenance if no values are set.)