## 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
if ((node.effectTag & Placement) !== NoEffect) {
          return MOUNTING;
        }
      }
    } else {
      while (node.return) {
        node = node.return;
      }
    }
    if (node.tag === HostRoot) {
       T
       r
      return MOUNTED;
    }
     If we didn't hit the root, that means that we're in an disconnected tree
     that has been u
    return UNMOUNTED;
  }
   This function is copied from React and should be kept in sync:
   https:github.com/facebook/react/blob/master/packages/react-reconciler/src/ReactFiberTreeReflection.js
   It would be nice if we updated React to inject this function directly (vs just indirectly via findDOMNode).
   BEGIN copied code
  function findCurrentFiberUsingSlowPathById(id: number): Fiber | null {
    const fiber = idToFiberMap.get(id);
    if (fiber == null) {
      console.warn(`Could not find Fiber with id "${id}"`);
      return null;
    }
    const alternate = fiber.alternate;
    if (!alternate) {