test: refactor type tests into a separate fixture

[danielroe]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This adds two new type test fixtures and removes type-only content from the basic fixture. This is part of a bigger reworking of the test fixtures to make it easier to understand what's going on.

It also contains a fix for useRoute and useRouter when used without the pages/ integration (which otherwise reverted back to any).

📝 Checklist

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