Add staged CABLE driver for advanced configurations

[Whyborn]

This driver is intended to facilitate spin-up CABLE configurations, which involve usually many stages with differing science configurations. An example experiment exists here, with some documentation: Staged_CABLE

[pep8speaks]

Hello @Whyborn! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers:

Comment last updated at 2024-09-24 12:38:22 UTC

[Whyborn]

I'll add some tests before requesting another review.

[aidanheerdegen]

Are you ready for another review @Whyborn?

[Whyborn]

I had requested another one, but I have been doing some thinking since the Payu workshop session to improve the handling of restarts. I'll cancel the current request and add a new one after I make (or not make) some changes.

[Whyborn]

I've made some adjustments to the way we retrieve the restarts, see the unresolved conversation. I've added tests to capture most of the desired functionality, but I was struggling to build a good test for retrieving restarts.

[aidanheerdegen]

I think I'm at the end of my utility as a reviewer. I see @ccarouge has a few more suggestions, but after that probably best to merge it and start using it and iterate if there are problems, or improvements required. You're not touching any other drivers, so it's fairly side-effect free and you can test it, as can others.