Harden decorators class methods delegation

Decorator does not play nice with `class` instance method (it does not
forward), we have to define an instance methods to access these
attributes.

Moreover, `model_name` renders the parent class instead of child, make
it global in main decorator to avoid this error.

Author: skelz0r

app/decorators/application_decorator.rb

@@ -1,6 +1,8 @@
 class ApplicationDecorator < Draper::Decorator
   delegate :t, to: I18n
 
+  delegate :model_name, to: :object
+
   # Define methods for all decorated objects.
   # Helpers are accessed through `helpers` (aka `h`). For example:
   #

app/form_builders/authorization_request_form_builder.rb

@@ -40,7 +40,7 @@ def info_for(block)
   def contacts_infos(contacts = nil)
     return if @template.namespace?(:instruction)
 
-    contacts ||= @object.class.contact_types
+    contacts ||= @object.contact_types
 
     dsfr_accordion(
       I18n.t('authorization_request_forms.default.contacts.info.title'),

app/form_builders/dsfr_form_builder.rb

@@ -193,7 +193,7 @@ def hint_for(attribute)
   end
 
   def label_value(attribute)
-    @object.class.human_attribute_name(attribute)
+    (@object.try(:object) || @object).class.human_attribute_name(attribute)
   end
 
   def enhance_input_options(opts)

app/models/concerns/authorization_core/contacts.rb

@@ -31,7 +31,10 @@ def self.contact(kind, validation_condition: nil)
           contact_types << kind
         end
       end
-
     end
   end
+
+  def contact_types
+    self.class.contact_types
+  end
 end

app/views/authorization_request_forms/shared/_contacts.html.erb

@@ -2,7 +2,7 @@
 
 <div class="fr-container-fluid">
   <div class="fr-grid-row">
-    <% @authorization_request.class.contact_types.each do |contact_type| %>
+    <% @authorization_request.contact_types.each do |contact_type| %>
       <%= render partial: 'authorization_request_forms/shared/contact', locals: { contact_type:, f: } %>
     <% end %>
   </div>

spec/factories/authorization_requests.rb

@@ -11,7 +11,7 @@
 
     after(:build) do |authorization_request, evaluator|
       if authorization_request.need_complete_validation? || evaluator.fill_all_attributes
-        authorization_request.class.contact_types.each do |contact_type|
+        authorization_request.contact_types.each do |contact_type|
           {
             'family_name' => "Dupont #{contact_type.to_s.humanize}",
             'given_name' => "Jean #{contact_type.to_s.humanize}",