request: add support for parsing and matching suffixes

Since the times of XML media often have a suffix, for example `application/vnd.oai.openapi+json`. This conveys separate information on syntax and semantics.

Ability to match by group and suffix (in the example: `application`, `json`) would let applications to communicate the exact media type, and libraries to process such content in a generic way.

该 issue 没有指出文件、测试或入口点。首先定位用于解析和匹配媒体类型的 Python 函数及其测试，然后跟踪 `application/vnd.oai.openapi+json` 的处理方式；完成的标准是匹配可以使用其组和 `json` 后缀，同时保留完整的媒体类型。

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