CLI Documentation update / CLI small bug fixes and format updates

[evrose54]

Reviewer Checklist

• Required existing tests pass (ie full_test.sh, others as appropriate)
• Required unit tests modified for updated functionality
• NO REQUIRED integration tests (explain why not required)
• Required documentation added for new/modified functionality
• Required release notes added for new/modified functionality
• NO REQUIRED updates to other repos (explain why not required)

Related Issues

N/A

Testing Instructions

Run pytest -v /tests/unit_tests/commandline/

Summary

Bug Fixes / Formatting Updates:

This PR fixed small bugs and formatting inconsistencies with the CLI. Specifically,
this PR addressed the format of the output of 'geoips describe' commands, to make
the keys in the yaml output all be in title format rather than (some_val:) vs.
(Some Val:). In this PR we were working on getting CLI documentation up to date,
and discovered a bug with 'geoips list packages' where the '--columns' flag was not
actually working. This was a simple fix and that functionality is now working as
expected. Unit tests have been updated to address these changes.

  geoips/commandline/commandline_interface.py
  geoips/commandline/geoips_command.py
  geoips/commandline/geoips_describe.py
  geoips/commandline/geoips_list.py
  tests/unit_tests/commandline/test_geoips_describe_interface.py
  tests/unit_tests/commandline/test_geoips_plugin.py
  tests/unit_tests/commandline/test_geoips_list_packages.py

CLI Documentation Updates:

This PR updated the CLI documentation to reflect the current state of the CLI code.
Largely, this PR went through the documentation of the CLI commands and made sure
that what was documented matched what would actually happen when that command was
ran. There was a duplicate entry in the documentation that was removed as well.
modified:

  docs/source/userguide/command_line.rst

[mindyls]

Looks good