Add util for culling MPAS-Ocean and -Seaice restart files

[xylar]

This needs a new version of MPAS-Tools (not yet released) with https://github.com/MPAS-Dev/MPAS-Tools/pull/557

Checklist

• [x] User's Guide has been updated
• [x] Developer's Guide has been updated
• [x] API documentation in the Developer's Guide (api.rst) has any new or modified class, method and/or functions listed
• [ ] Documentation has been built locally and changes look as expected
• [x] Document (in a comment titled Testing in this PR) any testing that was used to verify the changes

[xylar]

Testing

I ran this in:

/lcrc/group/e3sm/ac.xylar/compass_1.2/chrysalis/e3smv3-meshes/icosxisc30e3r7/ocean/utility/cull_restarts/cull

using the following restart files:

/lcrc/group/e3sm2/ac.wlin/E3SMv3/20231209.v3.LR.piControl-spinup.chrysalis/archive/rest/2001-01-01-00000/20231209.v3.LR.piControl-spinup.chrysalis.mpaso.rst.2001-01-01_00000.nc
/lcrc/group/e3sm2/ac.wlin/E3SMv3/20231209.v3.LR.piControl-spinup.chrysalis/archive/rest/2001-01-01-00000/20231209.v3.LR.piControl-spinup.chrysalis.mpassi.rst.2001-01-01_00000.nc

[xylar]

@cbegeman, I agree. Let's get this merged and we can tweak if necessary.

[xylar]

@cbegeman thanks so much for the review!