Fixes #36830 - transform_vars on preseed_path

Co-Authored-by: quartsize

Fixes #33469 - current stream for Flatcar

Refs #31059 - cleanup Environment from tests

Removes Environment related notes from tests, mostly just Host being
uselessly provided an environment.

Fixes #27604 - added Fedora|Redhat CoreOS and IM

Fixes #31946 - support for S390x

On S390 kernel and initramdisk are at a different path and with different names: images/kernel.img and images/initrd.img. Foreman operating system model must reflect that in order to download Anaconda installer to TFTP.

Co-authored-by: Ewoud Kohl van Wijngaarden <ewoud@kohlvanwijngaarden.nl>

Fixes #31016 - refresh registries after plugin testing (#8055)

Fixes #31016 - refresh registries after plugin testing

Introduce mechanisms to refresh the plugin registries.
We pollute these during plugin mechanisms testing and it never gets cleaned up.
This makes sure we clean mocks and stubs from the registries.

fixes #29432 - add flatcar os support

Fixes #29349 - Fix Layout/SpaceInsideArrayLiteralBrackets cop

Fixes #28965 - calculate PXE UID from OS version

Fixes #28846 - PPC64 pxedir location

Fixes #28561 - Configure and fix Layout/AlignArguments cop

Fixes #27249 - flip the comma cop

Fixes #26949 - Use $version instead of $release for FreeBSD

The `$release` variable only exists for Debian and Solaris. On FreeBSD, the @initrd macro should use `$version`.
Some other small fixes for the FreeBSD OS were added, as well as some tests.

fixes #26842 - altlinux: fix mediumpath

fixes #26796 - coreos: url_for_boot

Refs #19768 - Fix Layout/ClosingParenthesisIndentation cop

Fixes #19768 - Fix Layout/ClosingParenthesisIndentation cop

Fixes #25733 - PXE uid generated from pxedir

fixes #25852 - coreos mediapath vars are interpolated

Fixes #24728 - Support Huawei VRP

QUIRK: Only supports tokenless built URL

Fixes #19389 - Add medium_uri provider

Fixes #19389 - Added medium hash to TFTP files

Fixes #19789 - fix Layout/SpaceAroundOperators cop

Refs #22164 - use cheaper FactoryBot methods

• Refs #22164 - FactoryBot.build -> FactoryBot.build_stubbed

• Refs #22164 - FactoryBot.create -> FactoryBot.build

in
- test/unit/*
- test/models/shared/taxonomies_base_test.rb
- test/controllers/hosts_controller_test.rb

Fixes #21424 - use factory_bot_rails

fixes #16557 - move tests into modern Rails layout

Models, controllers, mailers and helpers are now in test/ subdirs
matching app/ subdirs. Service, miscellaneous and old test/lib/ tests
are now in test/unit/ separated from models, which obsoletes the custom...