Packaging changes

Summary:
This change has a few changes in the way our MacOS app was built and packaged.

- Instead of placing the Node binary inside the MacOS folder, place it inside the Resources folder. This is more in compliance with how an app is bundled. Also, with the added benefit of making it a resource which makes it eligible for code signing.
- Both, Node binary and server bundle are placed in the right location before building the MacOS app. By doing this, we ensure the app is not modified after the built process which messes up with code signing, if in place.

Reviewed By: antonk52

Differential Revision: D51568778

fbshipit-source-id: 0b1b0ad9947550ddf0f6d4b04e5aff41f7edcdee

desktop/scripts/paths.tsx

@@ -10,6 +10,7 @@
 import path from 'path';
 
 export const rootDir = path.resolve(__dirname, '..');
+export const sonarDir = path.resolve(__dirname, '..', '..');
 export const appDir = path.join(rootDir, 'app');
 export const browserUiDir = path.join(rootDir, 'flipper-ui-browser');
 export const staticDir = path.join(rootDir, 'static');