fix(serveStatic): automatically use Content-Encoding: gzip for .gz static files

[kricsleo]

🔗 Linked issue

resolves #3379

❓ 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

This PR improves the serving of static files for .gz files with automatically set Content-Encoding: gzip response headers. We can also add other types of encodings for compressed files if needed.

📝 Checklist

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