fix: statusCode in rootRedirect not working with strategy 'prefix'

[BobbieGoede]

🔗 Linked issue

• statusCode in rootRedirect not working with strategy 'prefix' #2758

❓ 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

Resolves #2758

I think the rootRedirect.statusCode was ignored because the request was redirected twice, once from / to the configured rootRedirect.path (e.g. about) with the statusCode, then again because /about doesn't exist for strategy prefix so it will be redirected to /en/about while ignoring rootRedirect configuration, as it's no longer redirecting on root.

This PR changes rootRedirect to try and translate the redirect path, so that a single redirection happens with the configured status code.

📝 Checklist

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

[kazupon]

This PR has passed testing, so I think the logic is fine. Once you have fixed my review point, you can merge them!