feat(events): bodyValidator and queryValidator event arguments

[DallasHoff]

🔗 Linked issue

unjs/nitro#2244

❓ 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)
• [x] ✨ 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

These changes introduce bodyValidator and queryValidator options to defineEventHandler. These can be passed validation functions, such as a Zod schema's parse method, to validate request bodies and query parameters and type them in the handler.

export default defineEventHandler({
  bodyValidator: z.object({
    id: z.string()
  }).parse,
  handler: async (event) => {
    const { id } = await readBody(event);
    // id is inferred as a string now
  }
});

This will also allow Nitro to type the body and query options of $fetch since the required types of the body and query can now be inferred from the event handler, opening the door to...

await $fetch('/foo', {
  method: 'POST',
  body: {}, // <-- body inferred as { id: string } from the Zod Schema, so this is a TS error
});

See the associated pull request to Nitro: unjs/nitro#2405

📝 Checklist

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