Function toString

tests/unit-tests/Source/TestUtils.cpp:9–17

doctest::String toString(const Vec2& value) {
    std::string s;
    s.append("(");
    s.append(std::to_string(value.u));
    s.append(", ");
    s.append(std::to_string(value.v));
    s.append(")");
    return s.c_str();
}

doctest::String toString(const Vec3& value) {
    std::string s;