Fixes #15405 - Moved puppet UI to helpers

Fixes #14714 - Make inherited Puppet Classes more apparent

To better recognize which Puppet Classes are inherited for Host
or Hostgroup they are under a sub-heading as a seperated list.

Fixes #3551 - Show unavailable Puppet Classes in Host Group edit

Puppet Classes can be assigned to a Host Group even if they are
not available in the set environment.

The Classes persist through out changes of the environment,
but were previously hidden from the UI this changes that....

Fixes #6952 - Set hostgroup after provisioning from pxe

After hostgroup provisioning, when the machine has registered
with foreman, it should be in the same hostgroup.
to achieve this behavier, the fact foreman_hostgroup should be
added to hostgroup provisioning template

Fixes #17330 - skip admin email if it's unknown

When admin user is being seeded the Setting might not exist at that
moment. We can't just create it with value, since the setting would
be invalid because of other attributes. Therefore we split settings
creation from the setting list so we could create it from seed too....

Fixes #16782 - reset dhcp record cache after mac change

Fixes #17864 - Show smart proxy errors on unattended fail

If your proxy is has some error (like misconfigured sudoers, puppet not
available, etc...) and you try to boot a host through unattended
mode [1], the exception will not show up when you try to fetch the...

Fixes #17680 - templates_used host helper

templates_used contains the names of all of the provisioning templates
kickstart used during a host build. This allows users to be able to
show the name of a provisioning template during PXEBoot, for example

Fixes #15403 - moved puppet to a concern in hosts UI controller

Fixes #17457 - multiple_checkboxes doesn't work with orgs/locs

multiple_checkboxes calls ActiveModel::Naming on associations that could
be simply "Taxonomy". This results on a 500 error 'undefined method
`taxonomies' for #<Filter:0x005593624bdd18>' (or whatever other class...