What's not working?

Mantine migrated to using css in v7 and is now requires additional setup, i.e. inclusion of mantine css file and postcss config.

Related #9261

How do we reproduce the bug?

1. In a RW project setup Mantine yarn rw setup ui mantine
2. In any page/component import and use a mantine component
3. See that the component is unstyled

What's your environment? (If it applies)

No response

Are you interested in working on this?

• I'm interested in working on this