feat(app): onRequest, onBeforeResponse and onAfterResponse global hooks

[pi0]

🔗 Linked issue

Resolves #447

❓ 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 adds 3 new global hooks (options) onRequest(event), onBeforeResponse(event, { body }), onAfterResponse(event, { body }?) useful for debugging and request/response interception.

Notes:

• All hooks support async but it is highly discouraged to avoid Promises and block all requests
• The onResponse hooks, only receive response with body when a handled directly returns it (not when using send* methods).
• Only one hook is supported in h3 level. Frameworks can leverage unjs/hookable to support more advanced integrations.

📝 Checklist

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

[codecov]

Codecov Report

Merging #482 (3cb4a43) into main (21ed8d1) will increase coverage by 0.30%.
The diff coverage is 87.50%.

@@            Coverage Diff             @@
##             main     #482      +/-   ##
==========================================
+ Coverage   82.25%   82.56%   +0.30%     
==========================================
  Files          28       28              
  Lines        3206     3234      +28     
  Branches      489      495       +6     
==========================================
+ Hits         2637     2670      +33     
+ Misses        569      564       -5     

Files Changed	Coverage Δ
src/app.ts	97.42% <87.50%> (-0.53%)	⬇️

... and 1 file with indirect coverage changes