Fast refresh

Summary:
This diff enables optional [Fast Refresh](https://reactnative.dev/docs/fast-refresh) for Flipper in dev mode. It can be opted-in using additional argument "--fast-refresh": `yarn start --fast-refresh`. I've copy-pasted the most part of implementation from React Native with some minor changes.

I made this optional for now as it works not ideally. In most cases which I checked it works fine, however for some files it falls back to full refresh (e.g. when `desktop/plugins/network/index.tsx` changed) and sometimes doesn't refresh content even after change detected and re-compiled (e.g. when `src/ui/components/searchable/Searchable.tsx` is changed, Network plugin which is dependent on it is not refreshed automatically).

State from redux is restored after fast refresh, but local state in class-based components is cleared. For function-based components local state is also stored, so it's an additional point to make plugins components functional :)

Also, for now there is no UI for Fast Refresh (loading indicator etc), information is just logged to console.

Changelog: Experimental support for Fast Refresh in dev mode can be enabled by `yarn start --fast-refresh`.

Reviewed By: jknoxville

Differential Revision: D20993073

fbshipit-source-id: 65632788df105a85fac0b924b7808120900b349e

desktop/static/compilePlugins.ts

@@ -41,7 +41,13 @@ export default async function (
   reloadCallback: (() => void) | null,
   pluginCache: string,
   options: CompileOptions = DEFAULT_COMPILE_OPTIONS,
-) {
+): Promise<CompiledPluginInfo[]> {
+  if (process.env.FLIPPER_FAST_REFRESH) {
+    console.log(
+      '🥫  Skipping loading of third-party plugins because Fast Refresh is enabled',
+    );
+    return [];
+  }
   options = Object.assign({}, DEFAULT_COMPILE_OPTIONS, options);
   const defaultPlugins = (
     await fs.readJson(path.join(__dirname, 'defaultPlugins', 'index.json'))