feat: multiple locales on multiple domains

[DarthGigi]

🔗 Linked issue

#1161

❓ 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

Resolves #1161 by allowing the same locale on multiple domains. Eg:

NL domain:
https://mydomain.nl/ -> https://mydomain.nl/ (nl language)
https://mydomain.nl/en -> https://mydomain.nl/en (en language)
https://mydomain.nl/de -> https://mydomain.nl/de (de language)

https://mydomain.nl/nl -> https://mydomain.nl/nl (404)

DE domain:
https://mydomain.de/ -> https://mydomain.nl/ (nl language)
https://mydomain.de/en -> https://mydomain.nl/en (en language)
https://mydomain.de/nl -> https://mydomain.nl/de (de language)

https://mydomain.de/de -> https://mydomain.de/de (404)

📝 Checklist

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

[DarthGigi]

I've fixed the tests, all tests should pass now. Documentation has been added as well.

[PetroSilenius]

This would be a great functionality! I noticed there's no requested reviews, maybe you could resolve the conflicts and request someone to review this? 😄

[DarthGigi]

This pull request has been deprecated, please see #3065