[ENH]: add path.sketch.{scale, length, randomness, seed} rcParams

Problem

Looking at #25796 and #26854, it might be helpful to be able to independently set the different parts of sketch and not just as a tuple. This is motivated by wanting to make plt.xkcd discouraged and wanting the cleanest alternative for passing in the sketch params.

Proposed solution

#25796 moves in this direction by allowing both

mpl.rcParams['path.sketch'] = (scale, length, randomness, seed)
mpl.rcParams[`path.sketch_seed'] = seed

and if we're OK w/ the other parameters getting their own rcParams then they can have a unified naming scheme. Alternatively, we can probably do the parsing so None = default but I don't like having to remember which position is which param.

Inizia leggendo le issue #25796 e #26854, poi esamina come viene gestito l’rcParam esistente path.sketch. Decidi se scale, length, randomness e seed debbano ricevere ciascuno rcParams denominati in modo indipendente oppure se utilizzare un altro approccio di parsing. Il lavoro sarà considerato completato quando lo schema di configurazione scelto sarà implementato in modo coerente e controllerà in modo indipendente i parametri di sketch.