Summary:
This PR aims to update the Inspector tool in React Native to use the new inspection APIs that have been added to the ReactNative renderer:
https://github.com/facebook/react/pull/9691
This PR also cleans up the code in `Inspector.js` so there's no usage of React's internals.
Closes https://github.com/facebook/react-native/pull/14160
Reviewed By: bvaughn
Differential Revision: D5129280
Pulled By: trueadm
fbshipit-source-id: b1b077c04f46b0f52cdea0e19b4154441558f77a