fix(Dropdown): active/inactive dropdown links

[zoobzio]

🔗 Linked issue

Resolves #982

❓ 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)
• ✨ 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

UDropdown component was not applying active styles for internal URLs. Passing the isActive slot prop down from the parent NuxtLink component allows the item to be active if the item link is the current page. This will not effect existing functionality as the item can also be active from the HMenuItem component.

📝 Checklist

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