feat: support inline mode for serveStatic

[pi0]

🔗 Linked issue

❓ 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

Extracted from #1863.

This new mode allows for edge conditions that it is only possible to serve static assets using their inline value.

Also makes refactors for future improvements in public asset plugin.

📝 Checklist

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

[codecov]

Codecov Report

Merging #1864 (75d6aa1) into main (923b6cd) will decrease coverage by 0.04%.
The diff coverage is 74.35%.

❗ Current head 75d6aa1 differs from pull request most recent head 077b445. Consider uploading reports for the commit 077b445 to get more accurate results

@@            Coverage Diff             @@
##             main    #1864      +/-   ##
==========================================
- Coverage   52.34%   52.31%   -0.04%     
==========================================
  Files         172      172              
  Lines       11882    11910      +28     
  Branches      910      908       -2     
==========================================
+ Hits         6220     6231      +11     
- Misses       5566     5582      +16     
- Partials       96       97       +1     

Files	Coverage Δ
src/types/nitro.ts	100.00% <100.00%> (ø)
src/rollup/plugins/public-assets.ts	88.07% <73.68%> (-4.61%)	⬇️

... and 2 files with indirect coverage changes