fix(app): use default error handler if onError does not handles reponse

[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

When a custom onError is in place and it does not handle response, it can cause pending responses. This PR changes implementation to wait on onError and try to handle response by h3 directly if it is not handled yet.

📝 Checklist

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

[codecov]

Codecov Report

Merging #478 (8189a42) into main (6e58103) will decrease coverage by 0.09%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##             main     #478      +/-   ##
==========================================
- Coverage   80.09%   80.01%   -0.09%     
==========================================
  Files          27       27              
  Lines        3025     3027       +2     
  Branches      451      453       +2     
==========================================
- Hits         2423     2422       -1     
- Misses        602      605       +3     

Files Changed	Coverage Δ
src/node.ts	83.33% <71.42%> (-2.39%)	⬇️

[pi0]

/cc @danielroe This should be safe as we mask console errors also. I would double check on rc please have it under your radar btw too if there are any regressions.