New callbacks to standardise some dim names

[jwarner8]

Fixes #982
Also added new fix for pressure level coordinate where surface recipes actively seek cubes where there is no pressure level data, i.e. pressure level list = [], but some AIFS cubes have the pressure coordinate called 'pressure_level' so this ensures cubes use 'pressure'.

Contribution checklist

Aim to have all relevant checks ticked off before merging. See the developer's guide for more detail.

• Documentation has been updated to reflect change.
• New code has tests, and affected old tests have been updated.
• All tests and CI checks pass.
• Ensured the pull request title is descriptive.
• Conda lock files have been updated if dependencies have changed.
• Attributed any Generative AI, such as GitHub Copilot, used in this PR.
• Marked the PR as ready to review.

[github-actions]

[jwarner8]

Fixes additional bug in get_cube_yxcoordname, where a spatial coordinate could be returned even though the dimension is scalar, and not a dim_coord. And thus using get_cube_yxcoordname may suggest cube is spatial (even though its been collapsed and spatial coords still exist as scalars in the metadata).

[jwarner8]

Actually, hold fire, still not getting coverage for https://tmpweb.net/LXAHrJ43vmBu/z_f5ac9763053bfad5_read_py#t349. I will look tomorrow...