[Feature Request] Update logging system to use format included in C++ standard

[`std::format`](https://en.cppreference.com/w/cpp/utility/format/format)
[`std::formatter<std::filesystem::path>`](https://en.cppreference.com/w/cpp/filesystem/path/formatter#Format_specification)

- remove 3rdparty/fmt and GTest
- adapt the code to use format version included in C++ standard

```cpp
#include <filesystem>
#include <format>
namespace logging
{
/* adapt code here */
};
```