Make Radio and RadioGroup labelDirection consistent and fix label type error

[BeeMargarida]

What package has an issue

@svelteuidev/core

A clear and concise description of what the bug is

• The labelDirection default values for Radio and RadioGroup are different
• There's an error with the label prop in RadioGroup, documented in this Discord support thread

In which browser(s) did the problem occur?

Firefox

Steps To Reproduce

Use this sample code: https://stackblitz.com/edit/sveltejs-kit-template-default-amdvqf?file=src%2Froutes%2F%2Bpage.svelte

Do you know how to fix the issue

Yes

Are you willing to participate in fixing this issue and create a pull request with the fix

Yes

Relevant Assets

No response

[BeeMargarida]

Label type error fixed in 3abcbfd, but the change in labelDirection is a breaking change, and will probably be addressed in the next version of the lib.