Functional tests for dataset/distribution UI forms

[grugnog]

User Story

As a user the dataset/distribution UI forms should work reliably as a way to create, edit and delete datasets.

Acceptance Criteria

• Datasets and distributions have end-to-end functional tests that test each field
• Tests include major code paths such as upload and URL resources, multiple resources
• Test should also cover the major validation fails (invalid form inputs, file formats etc) and other error messages that occur in the UI - if there are missing ones open follow up tickets