Engine: Organization: updates so that katello org is an extension of the core's org

This commit contains changes so that the katello organization
is now an extension of the core (foreman) organization.  The
result will be a single organization (taxonomies) schema.

Based on discussion with the team, since we are early on
with the engine work, we are purposely updating the existing
migration to remove 'katello_organizations' vs trying to
migrate data from katello_organizations to taxonomies.
This means users will need to katello:reset and
then db:migrate / db:seed.
Engine: Organization: fixing tests to support core org with katello extensions

This commit is to fix the tests that are affected by the
changes to the code to support a core organization (foreman)
which is extended to support katello properties.

Note: the tests leverage the 'taxonomies' fixture from
the foreman core to provide a couple of organizations
to test with.
Engine: regenerate VCR cassettes after moving to unified org
Engine: organization_extensions: fix rubocop complaint
Engine: address PR 3463 comments from unifying to single Organization
Merge pull request #3463 from bbuckingham/engine-organizations

Engine: Organization: update so that katello org is an extension of the core org.