perf: improve body read performance

[usualoma]

This PR applies fixes to maintain compatibility with web standards for the request body optimization merged in #301.

It seems we can implement this without significantly reducing the performance gains, but it will likely require a considerable amount of code. Maintenance costs also look substantial.

============================================================
BENCHMARK RESULTS
============================================================

| Benchmark         | npm            | dev            | Difference  |
| ----------------- | -------------- | -------------- | ----------- |
| Average           | 50,527.59      | 61,093.99      | +20.91%     |
| Ping (GET /)      | 65,812.06      | 70,197.87      | +6.66%      |
| Query (GET /id)   | 64,671.18      | 69,099.75      | +6.85%      |
| Body (POST /json) | 21,099.52      | 43,984.34      | +108.46%    |

[usualoma]

Hi @yusukebe

It's worth noting that a considerable amount of code is required, but I don't believe the complexity is so overwhelming that it becomes unmanageable if issues arise. Considering the significant speed improvement, accepting this level of complexity as a trade-off seems reasonable. (Plus, we can leverage AI for maintenance.)

What do you think? If it's acceptable, please merge this.

With this PR, I assume my additions to pref/request-v2 (oops, I mistyped the branch name) are complete.

[yusukebe]

Hi @usualoma, I'll review this soon.

On my machine (MacBook Pro / M4 Pro) the benchmark result is below. Though, it is wonderful:

[yusukebe]

LGTM!

[yusukebe]

Hey @usualoma

Looks great to me! I'll merge this into the perf/request-v2 now. And, maybe, I will create a new branch to prepare for releasing v2. Thanks!

[yusukebe]

Hey @usualoma !

I created the v2 branch and opened a PR #316 to merge v2 into main. But the CI fails https://github.com/honojs/node-server/actions/runs/22981070902/job/66720784480?pr=316

This is because a CI did not run on this PR's branch, so you missed the error. Can you take a look at it and fix the code so it passes CI? Thanks.

[usualoma]

Oh, sorry, I forgot to test it after making some last-minute adjustments.

[yusukebe]

@usualoma No problem!