Update various parts of DevTools to account for the fact that the global "hook" might be undefined if DevTools didn't inject it (due to the page's `contentType`) it (due to the page's `contentType`)
* Update Flow to 0.84
* Fix violations
* Use inexact object syntax in files from fbsource
* Fix warning extraction to use a modern parser
* Codemod inexact objects to new syntax
* Tighten types that can be exact
* Revert unintentional formatting changes from codemod
* Add version 4 react-devtools and react-devtools-core packages which support both React Native and e.g. Safari or iframe DOM usage.
* Replaces typed operations arrays with regular arrays in order to support Hermes. This is unfortunate, since in theory a typed array buffer could be more efficiently transferred between frontend and backend for the web extension, but this never actually worked properly in v8, only Spidermonkey, and it fails entirely in Hermes so for the time being- it's been removed.
* Adds support for React Native (paper renderer)
* Adds a style editor for react-native and react-native-web