JSON representation for theme

[origami-z]

Catch all issue

### Tasks
- [ ] Create JSON representation
- [ ] Generate CSS to replace most of existing theme package content
- [ ] Publish JSON as part of npm release
- [ ] Write documentation how to integrate with 3rd party libraries (e.g. vanilla-extract for Mosaic, theme visualization)
- [ ] Lint tool to help pattern library lint CSS while theming
- [ ] Lint tool to check against Figma library (variables)

Some considerations

• Theme vs Theme next
• Potential different folder / file structure ?
• Handle deprecation
• Token naming difference between Figma and CSS

Tools

• https://v4.styledictionary.com/

Prototype in #3143