Reorganization of fv3core analytic test cases

Purpose

To generate a modular method for using and adding analytic test cases

Code changes:

File initialization.py, has an additional register and dataclass for initializing analytic test cases. If a user plans to run an analytic test case, the specific case will now be specified in the yaml file containing the configuration specifications. New file, analytic_init.py will select the initialization method correlated to the test case specified in the yaml file. General initialization methods for analytic test cases are now contained in init_utils.py

The files dycore_state.py and geos_wrapper.py have been moved outside of the initialization directory to the level of the pace/fv3core directory and pace/fv3core/wrappers respectively.

Requirements changes:

For use of analytic test case, user will have to update yaml file to specify the general type of analytic test case to be run: (example)

initialization: type: analytic config: case: baroclinic

Infrastructure changes:

No infrastructure changes

Checklist

Before submitting this PR, please make sure:

[ ] You have followed the coding standards guidelines established at Code Review Checklist.
[ ] Docstrings and type hints are added to new and updated routines, as appropriate
[ ] All relevant documentation has been updated or added (e.g. README, CONTRIBUTING docs)
[ ] For each public change and fix in pace-util, HISTORY has been updated
[ ] Unit tests are added or updated for non-stencil code changes

Additionally, if this PR contains code authored by new contributors:

[ ] The names of all the new contributors have been added to CONTRIBUTORS.md

NOAA-GFDL / pace