## The current behavior

The full value of the `key` is very difficult / impossible to find and use in the interface of the React Devtools.

![Kapture 2020-04-22 at 11 47 47](https://user-images.githubusercontent.com/1935696/79997715-25222680-84ba-11ea-97ba-51f1679a8c91.gif)

Only managed to find it by accident :(

## The expected behavior

The `key` is visible in the props list to the right.

### Detailed Proposal

As mentioned below in https://github.com/facebook/react/issues/18702#issuecomment-617924196

Add a light divider and new section in the props panel to the right.

Potentially also add a question mark that shows an explanation about the fact that things in this section are not really props.

Ref (Original implementation): https://github.com/facebook/react-devtools/pull/328
case 'not-found':
          
          break;
        case 'hydrated-path':
          
          element = store.getElementByID(id);
          if (element !== null) {
            if (currentlyInspectedElement != null) {
              const value = hydrateHelper(data.value, data.path);
              const inspectedElement = {...currentlyInspectedElement};
              fillInPath(inspectedElement, data.value, data.path, value);
              resource.write(element, inspectedElement);
              
              if (id === selectedElementID) {
                setCurrentlyInspectedElement(inspectedElement);
              }
            }
          }
          break;
        case 'full-data':
          const {
            canEditFunctionProps,
            canEditHooks,
            canToggleSuspense,
            canViewSource,
            hasLegacyContext,
            source,
            type,
            owners,
            context,