Adapt structure according to LSG

lib/widget/cost_types.rb

@@ -32,10 +32,15 @@ class Widget::CostTypes < Widget::Base
   def contents
     content_tag :div do
       available_cost_type_tabs(@subject).sort_by { |id, _| id }.map do |id, label|
-        type_selection = radio_button_tag('unit', id, id == @selected_type_id)
-        type_selection += label_tag "unit_#{id}", h(label)
-        type_selection
-      end.join('<br />').html_safe
+        content_tag :div, class: "form--field -trailing-label" do
+          types = label_tag "unit_#{id}", h(label), class: "form--label"
+          types += content_tag  :span, class: "form--field-container" do
+            content_tag :span, class: "form--radio-button-container" do
+              radio_button_tag('unit', id, id == @selected_type_id, class: "form--radio-button")
+            end
+          end
+        end
+      end.join('').html_safe
     end
   end
 end