"Save JSON" feature should be more flexible

[tetraptych]

Certain fields appear in the results of the "Save JSON" button that are no longer required for a dataset (i.e., languages: []).

Similarly, other useful fields are not populated at all (e.g., location).

Now that the frontend is flexible in terms of the fields displayed in the tooltip, the "Save JSON" feature should be flexible and use all provided fields. It should also not enforce the presence of fields that aren't required.

Addressing this issue will make the process of adding new datasets orders of magnitude easier.