Option to save best scores dict and model file (per estimator type) to disk

[EgorKraevTransferwise]

One could want to run for a subset of estimators first, and then extend the search to others, for example.
We could implement an option to save them to disk eg by having model_save_path and scores_save_path as optional arguments to AutoCausality(), and then have a filename derived from eg estimator name, time budget, and save timestamp, saved in that path if the path is not Null