refactor: reduce usage of event.node.res

[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

Following up #1511, this reduces dependency on event.node.res across nitro codebase. event.handled checks are now removed too since send utility is expected to take care of it (in rare cases there might be regressions since send is async but we might investigate anything related in h3 send util if happens). Main part remaining are timing and cachedEventHandler to fully decouple from node.

📝 Checklist

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

[codecov]

Codecov Report

Merging #1513 (29ef47e) into main (2ecd9fa) will decrease coverage by 0.03%.
The diff coverage is 53.33%.

@@            Coverage Diff             @@
##             main    #1513      +/-   ##
==========================================
- Coverage   76.22%   76.19%   -0.03%     
==========================================
  Files          73       73              
  Lines        7456     7462       +6     
  Branches      732      731       -1     
==========================================
+ Hits         5683     5686       +3     
- Misses       1772     1774       +2     
- Partials        1        2       +1     

Files Changed	Coverage Δ
src/dev/error.ts	21.81% <53.33%> (+11.61%)	⬆️

... and 1 file with indirect coverage changes