macOS: fix wstr ('codecvt_utf8<char32_t>' is deprecated) deprecations without 3rd party

[debugmenot]

Hi. there is a little patch to resolve at least macOS compilation issues such as: /CppServer/modules/CppCommon/source/string/encoding.cpp:298:31: error: 'codecvt_utf8<char32_t>' is deprecated [-Werror,-Wdeprecated-declarations] std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> convert; ^ /Library/Developer/CommandLineTools/SDKs/MacOSX14.4.sdk/usr/include/c++/v1/codecvt:187:28: note: 'codecvt_utf8<char32_t>' has been explicitly marked deprecated here class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 codecvt_utf8

without using 3rd party libs (ex boost or icu4c)

Needs testing...