Profiles are always synchronized when using DurationDiscretization = Discrete

[stefanbesler]

When implemented a unittest for struckig, I noticed that disabling synchronization is not working when using duration discretization.

How to reproduce:

TEST_CASE("discretization-nosync") {
    RuckigThrow<3> otg {0.01};
    InputParameter<3> input;
    OutputParameter<3> output;

    input.current_position = {0.0, 0.0, 0.0};
    input.target_position = {1.0, -3.0, 2.0};
    input.target_velocity = {0.2, 0.2, 0.2};
    input.max_velocity = {1.0, 1.0, 1.0};
    input.max_acceleration = {2.0, 2.0, 2.0};
    input.max_jerk = {1.8, 2.4, 2.0};
    input.duration_discretization = DurationDiscretization::Discrete;
    input.synchronization = Synchronization::None; // <-----

    Trajectory<3> traj;
    std::array<double, 3> new_position, new_velocity, new_acceleration;
    auto result = otg.calculate(input, traj);

    CHECK( result == Result::Working );
    CHECK( traj.get_duration() == doctest::Approx(4.5) );
    CHECK( traj.get_duration().get_profiles[0][0].t_sum.back() == doctest.Approx(2.38) ); // <-- This should not fail

    result = otg.update(input, output);
    output.trajectory.at_time(4.5, new_position, new_velocity, new_acceleration);
    CHECK( array_eq(new_position, {1.0, -3.0, 2.0}) );
}