chore: add constructor for TSPRandomInitializer

fix: iterate city positions by rows

refactor: use swap_rows in SwapPerturbaiton instead of swapping by indices

feat: add plotting of TSP

refactor: pass rng as argument

Instead of having the Rng stored
inside the structs, pass it through
the functions. This means it's no longer
necessary to pass perturbations etc. as mutable.

feat: init tsp_hw01