Restructure

See merge request starter-projects/react-starter!17

feat: Remove `style/css-loader` from base webpack config as different configs needed for prod. Add support for CSS files in production (previously caused server error).

Note; CSS files loaded via Loadable component will not <Link> automatically. Add <Link> manually to index files or ensure loaded on a none loadable component.

Combine redundant client configurations for modern builds into a single configuration object. Simplify webpack module exports and update optimization settings for better performance.

build: fix issue with loadable chunk names not being set in prod builds breaking SSR unless explicitly set in code with `webpackChunkName` magic comment

chore: Revert mode switcher due to SSR flashing. Investigate "Sec-CH-Prefers-Color-Scheme" header in future.

feat: Better content on welcome page (questionably). Styled Components light/dark mode instead of CSS.

Upgraded Babel packages and associated development dependencies to their latest versions. This includes updates for `@babel/cli`, `@babel/core`, and more, to ensure compatibility and leverage new features and bug fixes.

# Conflicts:
#	docs/DELIVERY_API.md
#	package-lock.json
#	package.json
#	public/index.ejs
#	src/app/redux/siteConfig/sagas.ts
#	src/app/routes/withEvents.ts