Make spack packages for CICE6, MOM6, WWIII, access3-share

[anton-seaice]

Split the existing access-om3-nuopc package into several components, to produce the same result as the access-om3-nuopc package, split into components.

[anton-seaice]

We want to be able to build both the MOM6/CICE6 standalone and access builds.

According to the spack docs, it looks like you can only use git hashes/tags from one repository - see https://spack.readthedocs.io/en/latest/packaging_guide.html#fetching-from-code-repositories

I think this means that we would have one spack package for each component, which points to the access-nri fork, and a seperate spack package (contributed to the upstream spack repo) for the upstream build ?

Should we prefix out packages with access- so we can have different packages for the upstream version in the future.

i.e there is an access-cice package in this repository and a cice package in https://github.com/spack/spack/tree/develop/var/spack/repos/builtin/packages ?

This seems like duplication, needing two spack packages for each model component ...