Support jsonData when adding a file to a dataset (api.upload_file)

[pdurbin]

The example at http://guides.dataverse.org/en/4.15/api/native-api.html#add-a-file-to-a-dataset illustrates that jsonData can be uploaded when adding a file:

curl -H "X-Dataverse-key:$API_TOKEN" -X POST -F 'file=@data.tsv' -F 'jsonData={"description":"My description.","directoryLabel":"data/subdir1","categories":["Data"], "restrict":"true"}' "https://example.dataverse.edu/api/datasets/:persistentId/add?persistentId=$PERSISTENT_ID"

The jsonData object allows the user to add additional metadata about the file:

• description
• file hierarchy ("directoryLabel")
• tags ("categories")

It would be great if api.upload_file supported this jsonData object.

[pdurbin]

Here's a real world use case: IQSS/dataverse-sample-data#5

[skasberger]

Partly implemented here: AUSSDA@ebdba4d