Small CLI Refactors needed in a future PR

[evrose54]

Requested Update

Description

This issue was created due to lingering comments on the #444 PR. Since that PR is a dependency of other PRs like #465 and #478 , we are going to wait to make those updates and finish them up in a separate PR once those have been merged. Since none of the comments address actual bugs, this is largely just a refactoring change and is good to wait until we merge the aforementioned PRs.

Checklist for Completion

Add to the following list for all comments that still need addressing.

• [ ] Use consistent naming for pkg in CLI Unit tests
• [ ] Address whether or not we want to use .extend(list) rather than += list. Personally I say we keep it as +=
• [ ] Address if we want to refactor all_possible_subcommand_combinations for CLI Unit Tests (See #648)
• [ ] Consider renaming all_possible_subcommand_combinations to something more accurate. Some include all cases; some are stochastic. (See #648)
• [ ] Consider making separate geoips unit / unit-test command rather than geoips test unit-test (not important right now as this functionality has been completely commented out)
• [ ] Move GeoipsExecutableCommand:_get_registry_by_interface_and_package to PluginRegistry class
• [ ] Consider refactoring tabulate portions of GeoipsList to reduce some code duplication
• [ ] Fix formatting of usage when a command is called incorrectly. For example, geoips list prints usage that is poorly formatted.
• [ ] Consider refactoring GeoIPS Subcommand Classes into a different hierarchical organization. This will need ample discussion. (See #457)
• [ ] Attach pre-build script to plugin_package installation process, that generates a text file (or other suitable file type) which includes the installation time of that certain package. If this installation time is newer than the modification time of registered_plugins.json of that package (if it even exists), then run / rerun create_plugin_registries to ensure GeoIPS is in a correct / valid state. (See #647)

All bullets in the list above that don't have a referenced issue are either described in their entirety above or will most likely not be addressed / relevant in the future. For example, the point talking about geoips test unit-test doesn't have an issue as that functionality will likely be removed.

[evrose54]

A larger change (I'll create another issue later) will be implementing logging within the CLI. See Jeremy's comment at https://github.com/NRLMMD-GEOIPS/geoips/pull/444/files#r1592810697