C++20 may require a large portion of code to be upgraded

[Xaymar]

Description

C++20 removes the ambiguity of std::string meaning both ASCII as well as UTF-8 and instead introduces char8_t, std::u8string and similar new functionality. This cleans up the code drastically as all code page conversion is done by the C++ runtime instead of having to juggle ASCII and UTF-8 without any clear difference. This mainly affects std::filesystem::path code, but might also affect other parts of the code base that might end up resolving unicode strings.

Checklist

• I am willing to pay someone to implement this feature.
• This feature absolutely can't be done with already existing features.