[5.0] Native PSR7 spec support

[doubaokun]

To better support upper layer frameworks and application, http messages should follow PSR7 spec.

[aiira-co]

Wouldn't it be better to create a PSR7 Bridge lib to just convert swoole http message to standard psr7

[aiira-co]

Wouldn't it be better to create a PSR7 Bridge lib to just convert swoole http message to standard psr7

I do that with my framework at https://github.com/aiira-co/spatial-core/tree/main/src/swoole and uses it like so at index

[doubaokun]

Thanks, by providing the native support will save the overhead of the downstream frameworks.

[doubaokun]

Supported from v22 which will be available soon.