refactor: clean up and reduced code size

[EdamAme-x]

Some cleanups and commonization of Object.create(null) to reduce the amount of code.

18.5kb -> 18.1kb

The author should do the following, if applicable

• [ ] Add tests
• [x] Run tests
• [x] bun run format:fix && bun run lint:fix to format the code
• [ ] Add TSDoc/JSDoc to document the code

[codecov[bot]]

Codecov Report

:x: Patch coverage is 93.47826% with 3 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 91.67%. Comparing base (190e122) to head (0741688). :warning: Report is 207 commits behind head on main.

Files with missing lines	Patch %	Lines
src/router/trie-router/node.ts	89.28%	3 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3711      +/-   ##
==========================================
- Coverage   91.70%   91.67%   -0.03%     
==========================================
  Files         159      159              
  Lines       10158    10150       -8     
  Branches     2855     2885      +30     
==========================================
- Hits         9315     9305      -10     
- Misses        842      844       +2     
  Partials        1        1              

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[EdamAme-x]

Oddly, coverage shows a line of code that doesn't exist 👀

[yusukebe]

Not only this, but we would like to reduce the amount of code by using a common single method, e.g., new Response(). Please wait while I think about how to do it.

[EdamAme-x]

Okay. Common file or put them together at build time.