Fixes #33033 - shell_escape template macro

New template macro `shell_escape` using
Ruby's `Shellwords.shellescape` for safe shell strings.

Use `shell_escape` for user input variables
in registration templates (`global` & `host_init`)

Fixes #33004 - Registration - Refresh subscription data

Fixes #33155 - Drop Spice XPI support

This plugin is no longer maintained and relied on Xulrunner support in
Firefox. That means that with Firefox 60 or newer it's broken.

Fixes #31751 - make enable-epel false by default

Users should explicitly opt-in to have EPEL enabled on their systems

Fixes #33038 - add bmc_available to host show API

Fixes #33042 - salt-minion is installed in saltstack_setup

Refs Refactor #31059: Extract Environments models - drop environments from Taxonomy

Removes taxation of Environment.

Refs #31059 - drop environments Host extensions

Removes uses of environment from Host

Refs #31055 - drop puppetclasses_or_envs_changed view

Added to the plugin in https://github.com/theforeman/foreman_puppet/pull/133

Fixes #32091 - drop Environment from Host overview

Extracted in https://github.com/theforeman/foreman_puppet/pull/124