TypedDict with patterns as key names

I'm not sure if I should open an issue here at typing, please let me know if there is something better.

WSGI type defines. https://gist.github.com/abersheeran/f3723029387fe7f6584c6b157b90a50a

When writing a more static WSGI definition based on PEP3333, I discovered such a problem. TypedDict cannot describe the HTTP_* keys in the WSGI specification. I know that one of the original intentions of TypedDict is to prevent typing the wrong keys. But can we add an option (for example: allow_undefined=True) to allow this actual problem?

首先检查链接 gist 中 TypedDict 的行为和 WSGI 类型定义，并以 PEP3333 作为需求参考。确定支持 HTTP_* 键名是否需要新选项或其他 typing 设计，然后与 typing maintainers 确认该提案；当已确定一个获接受的方案以及相应的测试或文档时，即视为完成。