Add integrate and differentiate methods to States

[domire8]

For several state types, we already have multiplication and division operators with std::chrono::nanoseconds that represent integration and differentiation. It would be nice to add overloaded methods like

CartesianPose CartesianTwist::integrate(double dt);

CartesianPose CartesianTwist::integrate(std::chrono::nanoseconds dt);

And the same for differentiate, for all applicable states

[domire8]

FYI @bpapaspyros