simplify ice MPI layout and add cold_start dirs for ocean and ice

[NeilBarton-NOAA]

Description

Updates of branch for low res model PR discussion.

• script MPI options for CICE
• add cold start directories for ice and ocean for cycled system
• add EPS_IMESH option
• small scripting changes

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

first warm and cold forecast in cycled system tested on hera. Forecasts were not successful, but errors not caused by changes.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes need updates to the documentation. I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing tests pass with my changes
• Any dependent changes have been merged and published