Incorporate NOAA-EMC/spack-helpers

[AlexanderRichert-NOAA]

NOAA EMC is now maintaining some custom Spack commands: https://github.com/NOAA-EMC/spack-helpers
The intent is to use these in a few contexts, including spack-stack, but also for miscellaneous CI and other applications. I'd like to incorporate these into spack-stack, mainly to support NCO/WCOSS2 deployments, though I suspect some of the commands especially for validating environments will be of use. It's not strictly necessary, but I would propose using the duplicate detection and go/cargo dependency-fetching functionality in those custom commands/Python API rather than the scripts currently under util/.

There are a couple possible ways to incorporate the custom extension. The easiest from my perspective in terms of integration would be to add it as a submodule, which makes updating it over time easy, but would have the small down side that updating those custom commands would involve going through a separate repository. Alternatively, we/I could copy those modifications into the existing spack-stack extension, which is doable but would involve more work for me :)

[climbfuji]

We can chat about this tomorrow. My immediate reaction is that we would want those commands somewhere in the public JCSDA GitHub realm, though.