#59062 implements the UI for closure options and mapping. The form fields should be disabled when no connector is selected. <img width="1012" alt="Screenshot 2020-03-04 at 5 11 40 PM" src="https://user-images.githubusercontent.com/7871006/75893288-3f853f80-5e3b-11ea-86b7-0f3f55132c5e.png">
