Feature/refactor modular config

[cristiano-belloni]

Factor out Webpack configuration in separate files (parts) and use webpack-merge to merge them.

Configuration is now divided into:

1. Style loaders (order is essential here, so style loaders are essentially an atomic block)
2. Type app specific configuration (normal conf + plugin conf)
3. Type esm-view specific configuration (normal conf + plugin conf) + esm rewriting utilities
4. Development build (modular start) specific configuration (normal conf + plugin conf)
5. Production build (modular start) specific configuration (normal conf + plugin conf)
6. Base (common) configuration, separated into plugin conf and regular configuration
7. webpack.config file, which essentially parses the environment and collates the right parts with webpack-merge

---

• factor out style loaders
• factor out app conf
• factor out esm-view conf
• factor out production conf
• factor out development conf
• factor out base conf
• merge configurations

[changeset-bot]

🦋 Changeset detected

Latest commit: 906b441

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
modular-scripts	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[coveralls]

Coverage decreased (-0.03%) to 33.358% when pulling 906b441 on feature/refactor-modular-config into 902e03a on main.

[ayseenver]

There's a typo on "merge"

[cristiano-belloni]

Fixed, thanks!