Add expose_php option with reduced precision

Description

As @krakjoe pointed out at https://github.com/php/php-src/pull/3335, the popular default configurations are decided by package managers and hosting providers, and the default already has expose_php enabled.

But, we also know that those same package managers and hosting providers feel their only option is to turn this off as a sort of security through obscurity. This in turn can deminish global statistics (e.g. W3 Techs).

Perhaps we could offer a middleground that would appeal to some of the package managers (e.g. Debian, Fedora), and major hosting providers to no longer turn it off completely. For example:

X-Powered-By: PHP/8.2.9

… could be reduced to:

X-Powered-By: PHP

One could instead consider preserving major or major+minor version. But, I think an option that controls simply whether the version is obscured is more likely to receive broad adoption, and keeps the API simpler to maintain and to consume (also crawlers interpreting and aggregating this information).

/cc @Slamdunk @petk

まず、既存の expose_php 設定と、X-Powered-By ヘッダーを生成するレスポンスパスを追跡します。提案されている低精度の動作を、現在の有効および無効のケースと比較し、その後、関連する設定およびテストのエントリーポイントを特定します。対応するオプションでヘッダーを維持しつつ、そのバージョンを省略できれば完了です。