Make Autocut functionality more easily inspectable and accessible without having to run the whole model

[kuadrat]

Currently, autocut functionality (at least PhenologicalAutocut) requires a lot of setup on the part of the linked ModvegeSite object. Some of that setup is even hidden behind private function, so it has to be carried out manually if one wishes to just get the expected cut date based on meteo.

It would be nice to be able to debug autocut routines that don't depend on the model state without having to setup the whole ModvegeSite.

Given that only a subset of autocut routines even fulfills this condition, this is a low priority issue.