fix!: nuxt context injected function types

[BobbieGoede]

🔗 Linked issue

• Roadmap for v9 #3002
• _ctx.$localePath is not a function #2168

❓ 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

Should resolve #2168

This fixes the function types and names of the injected context functions, unfortunately fixing this is a breaking change.

I think I know of a way to remove the augmentations in plugins/i18n.ts but that will require larger structural changes, for now the changes in this PR should be sufficient to fix the issue.

📝 Checklist

• I have linked an issue or discussion.
• I have added tests (if possible).
• I have updated the documentation accordingly.

[kazupon]

LGTM!