Allows to revert changes applied in [54277] - temporary workaround for the failing Test NPM CI check on Windows.
Improvements included:
- generate combined asset files for both production and development
- store in the repository only the production version of the combined assets for packages, we use everything else only in development
- to make unit tests work, ensure that they ignore react fast refresh and use the production version of combined assets that are present in the source code
Props bernhard-reiter, jsnajdr, clorith, wildworks.
Fixes#56615.
git-svn-id: https://develop.svn.wordpress.org/trunk@54289 602fd350-edb4-49c9-b593-d223f7449a82