types: export SerializeTuple and SerializeObject

[noook]

🔗 Linked issue

#1138

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 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

We couldn't import the type SerializeObject from nitro as it's what's used as a response in useAsyncData when requesting nitro routes. This PR exports the types so that it's usable in a project

📝 Checklist

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