Switch to package exports for React packages

[rajsite]

Pull Request

🤨 Rationale

Switches to package exports in the react packages so dist/esm can be removed from the package names.

👩‍💻 Implementation

• Updated package.json exports config and switched to package type module
• Unrelated refactor: since we are on a modern node version which can import cjs from esm was able to remove the build step around the icon generation script, this can be done in the other packages but didn't do in this PR
• Also included the styles scripts in the built packages 😅

🧪 Testing

• The normal build exercises moduleResolution: bundler in an example app and added a test tsconfig.legacy.json to exercise moduleResolution: node.
• Checked the storybook tsconfig.tsbuildinfo and preview-stats.json for regressions on imports resolving to dist instead of src for turbopack

✅ Checklist

• I have updated the project documentation to reflect my changes or determined no changes are needed.

[rajsite]

@jattasNI bypassing for nights and weekends update to react package exports, can address feedback in follow-up