fix: Router should be Macroable

[ThisIsMissEm]

🔗 Linked issue

#80 — This was fixed in 7.x, but was broken during the refactor for 8.x which removed LookupStore.

❓ Type of change

• 🐞 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

This change aligns the Router with the published documentation for 8.x: https://docs.adonisjs.com/guides/basics/routing#router

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.
• I have added tests to prevent further ocurrences of this regression.

[thetutlage]

👍🏽