Make st_archive archive MOM6+DART output files

Doing data assimilation with CESM+DART generates many new types of output files,
which st-archive should archive, assuming they are named according to CESM conventions.
Many of the new files will be handled by the esp component code, but others are
more closely associated with the geophysical components and should be archived
with their files. We've chosen new file names in such a way that this can be done
with very small changes to
$component/cime_config/config_archive.xml
cime/CIME/XML/archive_base.py
A second small change is to make st-archive handle compressed files (*.gz).
A third suggested change is about the parsing of the bgc file names.
This has no effect on model calculations or existing output.

I developed and tested the changes in a recent (2025-4-22) cesm3.0_alphabranch.
I've committed them to a feature branch based on master and pushed it to my fork of MOM_interface.
I can include more details here, or in a PR when it's time for that.

I don't have permission to add Assignees, Labels, etc., so I'm hoping that someone will fill those in,
or give me permission to.

There's a somewhat related issue ( #238 ) about what the MOM filenames will actually be,
but this issue can be fixed independently of that.