Function stringify

lib/catch2/catch.hpp:1644–1646

        // Should be preferably called fully qualified, like ::Catch::Detail::stringify
        template <typename T>
        std::string stringify(const T& e) {
            return ::Catch::StringMaker<typename std::remove_cv<typename std::remove_reference<T>::type>::type>::convert(e);
        }

        template<typename E>
        std::string convertUnknownEnumToString( E e ) {