Add fix and test for metadata enable false bug

[jo-basevi]

This PR fixes the config option to disable metadata bug #426.
I’ve added a test that replicates the error.

Closes #426

[pep8speaks]

Hello @jo-basevi! 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! 🍻

Comment last updated at 2024-04-02 23:27:24 UTC

[jo-basevi]

As discussed, with @aidanheerdegen, have modified the the config.yaml, metadata: enable: false to set the experiment name for archival to either to the legacy control directory name or the configured experiment value in config.yaml. So payu will effectively behave as it did before UUID+Branching changes, i.e. no branching and no updating/generating metadata with UUIDs.

[aidanheerdegen]

Trying to untangle the code paths for various possibilities does my head in. It seems fine, and I prefer the clearer logic of no metadata == legacy (no UUID).