C++ 20 Module support

[Ariaszzzhc]

Currently compilers such as gcc, clang, and msvs have already provided support for C++ standard modules. So is there are any plan to support C++ 20 Module?

[uNetworkingAB]

Yes but the library itself is still only requiring/using C++17, so a jump to C++23 with std::move_only_function (heavily used) could be a good time to update all of that.

[kelteseth]

I have linked this issue regarding modules support to https://arewemodulesyet.org/ to track the progress of modules adoption in the c++ ecosystem. @uNetworkingAB uWebSockets would need to upgrade the build system as well, right? Because makefiles do not support modules.