Fixes #33121 - Registration command API & params with false values

Registration API for generating registration command
incorrectly ignores parameters with `false` boolean value.

Fixes #32415 - access only through SettingRegistry

Update and read the settings through SettingRegistry.
Adds a layer between controller and Model.
SettingRegistry is proxying the value parsing method to the model.

This lifts blocker for settings without DB record.

Refs #31059 - cleanup Environment from tests

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

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

Removes taxation of Environment.

Refs #31129 - drop Puppetclass from Host(group) API

Extracted in https://github.com/theforeman/foreman_puppet_enc/pull/106

Fixes #31129 - drop Host classes API

Extracted in: https://github.com/theforeman/foreman_puppet_enc/pull/103

Fixes #31732 - drop environment in TemplateCombination model

Extract Environment from TemplateCombination matrix as temporary solutin.
This should probably get dropped if favor of some better solution like direct set on hostgroup.

Though this will need to be reflected in foreman_puppet_enc plugin....

Refs #31733 - drop Environment assignmet API

Extracted in https://github.com/theforeman/foreman_puppet_enc/pull/100

Fixes #31369 - drop Environment fixtures usage

Do not use environment in tests, especially not the one from fixtures.

Host tests extracted in https://github.com/theforeman/foreman_puppet_enc/pull/94.

Fixes #30332 - Drop PuppetInfo

Drop what theforeman/foreman_puppet_enc#4 introduced to plugin.
Additional test refactorings, that are included here are https://github.com/theforeman/foreman_puppet_enc/pull/92.