Remove C++/CX from the codebase

[TheStormN]

C++/WinRT is now the recommended way to write UWP apps. Also C++/CX is not compatible with C++20.

I'm trying to migrate our project to C++20 which have dependency on cpprestsdk, but unfortunately the linker fails saying the standard libraries are incompatible. I'm getting this error:

vccorlib_lib_should_be_specified_before_msvcrt_lib_to_linker': value '1' doesn't match value '0' in msvcrt.lib

[pratikpc]

@TheStormN was this because your CMake App (if it was CMake) had the Windows Store environment variable turned on?

This is present in their CMakeLists.txt

[TheStormN]

@pratikpc Yes, we build our software for UWP too. But anyway, In one of the compiler updates, they've fixed the compatibility with C++20 and C++/CX.