Automate configuring optimizer and scheduler from config in scripts

[dhpitt]

Refactors some old repeated logic out of the training recipe scripts and puts it in neuralop/training/torch_setup.py

[dhpitt]

One question @JeanKossaifi - should these functions be in torch_setup or should they be in neuralop.utils?

[dhpitt]

Closing as the code is simple enough as-is.