DisCoCirc: Request for option to save and then reload previously computed tensornetwork contraction paths

[dimkart]

Request from @AnnaNPearson:

This is a request for a future release:

One thing that was used extensively to help the training and the time it took to train the discocirc experiment was the saving and re-loading of previously computed tensornetwork contraction paths. See section 3.2.1 and Appendix G of the paper https://arxiv.org/abs/2409.08777. The contractor we used was the random greedy one from tensornetwork https://tensornetwork.readthedocs.io/en/latest/contractors.html.