Merge to dev to form basis for release 0.2.0

[jr3cermak]

Working toward a release of 0.2.0 with the following highlighted changes:

• Adopt MOM6 license for the gridtools library.
• Add the ability for basic plotting of a single variable.
• Add the ability to write out FMS mosaic files.
  • Given MINIMUM_DEPTH, MAXIMUM_DEPTH and MASKING_DEPTH, the appropropriate masks are written to the exchange grids for tile1 for any given bathymetry grid.
• Ability to generate a topography/bathymetry grid from any data source.
• Ability to generate a topography/bathymetry grid from any data source and generate a roughness parameter (h2) using a mesh refinement method.
• Add the ability to convert a ROMS model grid to a MOM6 model grid.
• Use sphinx as the documentation pathway for the python library.
• HTML and PDF documentation rendered to https://mom6gridtools.readthedocs.io/en/latest/index.html
• Add cluster notes for chinook@UAF and triton@RU.
• Add installation notes on RasPi4, an aarch64 platform type for independent comparisons.
• References to papers and code being relocated to a central bibtex file used by sphinx (WIP).
• Fixing up references to previously implemented code (WIP).
• Remove extraneous whitespace.
• Implement a catalog system for data sources (WIP). It should not interfere with using files directly on a local system. Allow experimentation with alternate DAP service.