Make cell count heuristic

[altheaden]

Before this merge, we would compute the cell count using either a simple heuristic, or information from a previous step (e.g. opening the mesh file from the init step). In task parallel, we need to constrain the resources for all steps before any steps have run. This means won't have information (e.g. the exact cell count) from any previous steps when we need to constrain the resources for the given step at runtime. Therefore, we want to just use the heuristic every time instead of trying to read in the cell count from a file that won't exist.

Checklist

• [x] User's Guide has been updated
• [x] Developer's Guide has been updated
• [x] Documentation has been built locally and changes look as expected
• [x] Testing comment in the PR documents testing used to verify the changes

[altheaden]

I need to do another look over the changes in the documentation, but I haven't yet been able to build the docs yet. I'm marking this PR in progress until I finalize that, but the framework changes are finished.

[altheaden]

I tested this using the PR suite against a baseline, and everything passed as expected.

[xylar]

I made some modifications to the PR description. Feel free to further edit if they're not clear.

[xylar]

My testing passed on Chrysalis. I used a test-merge of this branch with main and using main as a baseline I ran:

  ocean/baroclinic_channel/10km/default
  ocean/baroclinic_channel/10km/decomp
  ocean/baroclinic_channel/10km/restart
  ocean/baroclinic_channel/10km/threads
  ocean/baroclinic_channel/10km/rpe
  ocean/global_convergence/qu/cosine_bell_with_viz
  ocean/global_convergence/icos/cosine_bell_with_viz
  ocean/inertial_gravity_wave/convergence
  ocean/manufactured_solution/convergence
  ocean/single_column/960km/cvmix
  ocean/single_column/960km/ideal_age

The manufactured_solution test case fails in the expected way because the convergence rate is less than desired. The other tests passed and results are bit-for-bit identical to the baseline.

[altheaden]

@xylar I tried to re-word things to make them a bit more understandable, let me know if that's more in line with what you were thinking.

[altheaden]

Also - I just built the docs and they look as expected.

[xylar]

@altheaden, I've assigned this to you. Merge when you're ready.

[xylar]

I'm changing the labels since the things changed here are all in polaris/ocean or docs. The "framework" for our purposes is anything in the polaris package and not in one of the component subpackages.