feat: normalize component file extension before creating file

[citrus]

🔗 Linked issue / Discussion

This change removes the duplicated .vue extension when creating a component and using a name with an extension.

❓ 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

When creating a new component named MyComponent.vue, Nuxtr would create a file named MyComponent.vue.vue. This PR normalizes the file name before creating the component, removing the duplicate extension.

📝 Checklist

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

[citrus]

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