feat: nuxi test supports setup globally

[antfu]

🔗 Linked issue

❓ Type of change

• [ ] 📖 Documentation (updates to the documentation or readme)
• [ ] 🐞 Bug fix (a non-breaking change that fixes an issue)
• [x] 👌 Enhancement (improving an existing functionality like performance)
• [ ] ✨ New feature (a non-breaking change that adds functionality)
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

It allows users to test their app using nuxi test without explicitly add setup in their test files.

📝 Checklist

• [ ] I have linked an issue or discussion.
• [ ] I have updated the documentation accordingly.

[netlify[bot]]

✅ Deploy Preview for nuxt3-docs canceled.

Name	Link
🔨 Latest commit	71957ac6b7c9eac0ecfd6d52c2254cdbfadd3c61
🔍 Latest deploy log	https://app.netlify.com/sites/nuxt3-docs/deploys/636d100709040b000891dc6b

[atinux]

It looks beautiful when looking at https://github.com/nuxt/framework/blob/feat/nuxt-test-global/examples/advanced/testing/tests/basic.test.ts

[AndrewBogdanovTSS]

Any updates on this PR?