refactor(pays): champ pays to use simple select

app/models/champs/pays_champ.rb

@@ -21,19 +21,42 @@
 #  type_de_champ_id               :integer
 #
 class Champs::PaysChamp < Champs::TextChamp
-  def localized_value
+  def to_s
+    formatted_value
+  end
+
+  def for_tag
+    formatted_value
+  end
+
+  def selected
+    code || value
+  end
+
+  def value=(code)
+    if code&.size == 2
+      self.external_id = code
+      super(APIGeoService.country_name(code, locale: 'FR'))
+    elsif code.blank?
+      self.external_id = nil
+      super(nil)
+    elsif code != value
+      self.external_id = APIGeoService.country_code(code)
+      super(code)
+    end
+  end
+
+  def code
+    external_id || APIGeoService.country_code(value)
+  end
+
+  private
+
+  def formatted_value
     if external_id
-      CountriesService.get(I18n.locale)[external_id].to_s
+      APIGeoService.country_name(external_id)
     else
       value.present? ? value.to_s : ''
     end
   end
-
-  def to_s
-    localized_value
-  end
-
-  def for_tag
-    localized_value
-  end
 end