feat: update error handler to latest upstream version

[wattanx]

🔗 Linked issue

#631

❓ 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)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

I have ported the contents of nitro/error.ts from Nuxt 3. (I'm not very confident, though.)

By implementing it in the playground as shown below, I was able to confirm that the contents of the headers are not missing.

layouts/error.vue

<template>
  <div>Error page: {{ headers }}</div>
</template>

<script setup>
const { ssrContext } = useNuxtApp()
const headers = useState('headers', () => ssrContext?.req.headers)

</script>

📝 Checklist

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

[danielroe]

you are on 🔥