fix: set nuxt context and normalise config as first module

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

📚 Description

Currently bridge module runs last (to ensure hooks are registered first) but it should probably normalize the config first. This PR adds a stub module to set nuxt context, set bridge option, and normalize layers.

Here's an example of a config that now works but previously didn't:

import { defineNuxtConfig } from '@nuxt/bridge'
import { useNuxt } from '@nuxt/kit'

export default defineNuxtConfig({
  buildModules: [
    function () {
      const nuxt = useNuxt()
    }
  ]
})

📝 Checklist

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