Maybe treat nested fields as JSON

[wfdd]

This whole semicolon-delimiting business is super flaky; but it's also human-readable. If we're gonna use JSON there's gotta be an easy way to edit it. Finally, there appears to be no way to specify a schema for JSON fields using the JSON Table Schema, which is a bummer. It might be a better idea to (a) convert the list to YAML or (b) split the offending fields into separate CSVs (-1 from an editing perspective).

The real issue here is that human input translates directly into machine-readable output. Ideally, there should be an editing interface fit for purpose. There might be something out there...