feat(admin-ui): Migrate Clarity to Tailwind

[dlhck]

Description

This PR removes the styles of the Clarity design system and replaces them with Tailwind. Styling is done in a backwards compatible way, which means that all clarity classes will be removed.

Important: This is heavy WIP and more like a PoC right now. We are especially thinking about backwards compatibility.

Relates to https://github.com/vendure-ecommerce/vendure/issues/2903

Breaking changes

There could be some breaking changes, if extensions rely on specific Clarity classes which were not used in the Admin UI initially.

Checklist

📌 Always:

• [x] I have set a clear title
• [ ] My PR is small and contains a single feature
• [ ] I have checked my own PR

👍 Most of the time:

• [ ] I have added or updated test cases
• [ ] I have updated the README if needed