fixes #18568 - replace deprecated AC::Parameters#update

The #update method in Rails 5 is returning a HWIA rather than the
ActionController::Parameters instance, causing keep_param to return the
wrong object type. It is also deprecated in 5.0, so replace it with a...

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

Fixes #16646 - Add ability to plugins to modify index scope

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...

fixes #16578 - make keep_param idempotent, remove duplicate call

Using host_params (and keep_param) twice was causing compute_attributes
to be deleted permanently out of `params`. keep_param now restores
elements it deletes, and the controller now only calls host_params once...

Fixes #16211 - show host autocomplete in audit search

Fixes #12634 - New HW Model flag pxe_loader

Implementation of

https://github.com/theforeman/rfcs/blob/master/text/0001-PXE-Booting-UEFI.md

In short, new host/hostgroup flag PXE loader is added to specify TFTP
DHCP filename and Foreman now orchestrates all PXE-capable templates...

fixes #15951 - pass interface compute_attributes

fixes #3917 - replace protected_attrs with strong parameters

Filtering of attributes has moved from the protected_attributes gem to
strong parameters in controller concerns, to be in line with current
Rails recommendations.

Concerns are shared between UI and both API controllers and list the...

Fixes #12193 - Stop using counter_cache for host[group] counts

This is aimed to prevent deadlocks caused by Rails' implementation of
counter_cache that is hit when multiple hosts are created or updated at
the same time. An added benefit is that the counters will now display...