Fixes #4608 - Added description field to role

Fixes #16624 - Make AuthSourceLDAP taxable

This allows users to set organizations/locations on AuthSourceLDAP
objects. That in itself might not be that useful, but it allows us to
follow on and assign the AuthSourceLDAP taxonomies to the users
autocreated through it.

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 #15846 - Renamed use_puppet_default to omit in LookupValue

fixes #16376 - use correct params filter for nested Puppet LKs

Fixes #7806 - allow taxonomy association on role level

Fixes #16264 - Template combinations cannot be created

Currently, strong parameters is not allowing passing the nested
attributes required to ProvisioningTemplate to create
TemplateCombinations through the UI.
The fix is as simple as permitting those parameters in a 'nested'...

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...