Have a look at the mockup (https://redhat.invisionapp.com/share/SVMB0QW6MR9#/screens/305421181) and add buttons to the structure view to add and edit resolvers. This is not about implementing the action when the buttons are clicked, but only to add those buttons. They should allow to create a resolver when none exists. They should allow to edit or delete a resolver when one exists.

For this you will need some logic to map existing resolvers. Take a look at the POC where this part was extracted into a separate react component: https://github.com/pb82/data-sync-ui/blob/resolvers/ui/components/schema/TypeList.js

We can use buttons or icons, just make it look good.