Function format

tests/test_record_format.cpp:90–95

template <typename... T>
std::string format(fmt::format_string<T...> pattern, T&&... args)
{
    Record record;
    record.Format(pattern, std::forward<T>(args)...);
    return record.message;
}

template <typename... T>
std::string store(fmt::format_string<T...> pattern, T&&... args)