Fix MSVC warnings in utils\*

[obligaron]

This reduces warnings by 14 (from 297 to 283)

There are some remaining warnings in utils left.
I'm not sure how to handle them the best way:

  [446/650] Building CXX object Source\CMakeFiles\libdevilutionx.dir\utils\console.cpp.obj
devilutionX\Source\utils\console.cpp(33): warning C4267: 'argument': conversion from 'size_t' to 'DWORD', possible loss of data

  [560/650] Building CXX object Source\CMakeFiles\libdevilutionx.dir\utils\file_util.cpp.obj
devilutionX\Source\utils\file_util.cpp(236): warning C4996: 'std::filesystem::u8path': warning STL4021: The std::filesystem::u8path() overloads are deprecated in C++20. The constructors of std::filesystem::path provide equivalent functionality via construction from u8string, u8string_view, or iterators with value_type char8_t. You can define _SILENCE_CXX20_U8PATH_DEPRECATION_WARNING or _SILENCE_ALL_CXX20_DEPRECATION_WARNINGS to suppress this warning.
devilutionX\Source\utils\file_util.cpp(277): warning C4996: 'std::filesystem::u8path': warning STL4021: The std::filesystem::u8path() overloads are deprecated in C++20. The constructors of std::filesystem::path provide equivalent functionality via construction from u8string, u8string_view, or iterators with value_type char8_t. You can define _SILENCE_CXX20_U8PATH_DEPRECATION_WARNING or _SILENCE_ALL_CXX20_DEPRECATION_WARNINGS to suppress this warning.

[glebm]

For u8path, it is fine to #define _SILENCE_CXX20_U8PATH_DEPRECATION_WARNING (right before #include <filesystem>).
That function is deprecated but there is no sensible alternative and it might even get un-deprecated.

For the utils/console.cpp:33 warning, static_cast the offending argument to DWORD.