Extract translation helper from translatable form views

So that individual form partials don't depend on the implementation
of how translations are deleted.

app/helpers/globalize_helper.rb

@@ -14,6 +14,18 @@ module GlobalizeHelper
     same_locale?(neutral_locale(I18n.locale), neutral_locale(locale)) ? "" : "display: none"
   end
 
+  def render_translations_to_delete(resource)
+    capture do
+      resource.globalize_locales.each do |locale|
+        concat translation_enabled_tag(locale, enable_locale?(resource, locale))
+      end
+    end
+  end
+
+  def translation_enabled_tag(locale, enabled)
+    hidden_field_tag("enabled_translations[#{locale}]", (enabled ? 1 : 0))
+  end
+
   def css_to_display_translation?(resource, locale)
     resource.translated_locales.include?(neutral_locale(locale)) || locale == I18n.locale ? "" : "display: none"
   end

app/helpers/site_customization_helper.rb

@@ -1,5 +1,9 @@
 module SiteCustomizationHelper
+  def site_customization_enable_translation?(locale)
+    I18nContentTranslation.existing_languages.include?(neutral_locale(locale)) || locale == I18n.locale
+  end
+
   def site_customization_display_translation?(locale)
-    I18nContentTranslation.existing_languages.include?(neutral_locale(locale)) || locale == I18n.locale ? "" : "display: none"
+    site_customization_enable_translation?(locale) ? "" : "display: none"
   end
 end

app/views/admin/banners/_form.html.erb

@@ -4,9 +4,7 @@
 
   <%= render 'errors' %>
 
-  <% @banner.globalize_locales.each do |locale| %>
-    <%= hidden_field_tag "delete_translations[#{locale}]", 0 %>
-  <% end %>
+  <%= render_translations_to_delete(@banner) %>
 
   <div class="row">
     <% date_started_at = @banner.post_started_at.present? ? I18n.localize(@banner.post_started_at) : "" %>

app/views/admin/budget_investment_milestones/_form.html.erb

@@ -2,6 +2,8 @@
 
 <%= form_for [:admin, @investment.budget, @investment, @milestone] do |f| %>
 
+  <%= render_translations_to_delete(@milestone) %>
+
   <%= f.hidden_field :title, value: l(Time.current, format: :datetime),
                              maxlength: Budget::Investment::Milestone.title_max_length %>
 
@@ -16,7 +18,6 @@
 
   <%= f.label :description, t("admin.milestones.new.description") %>
   <% @milestone.globalize_locales.each do |locale| %>
-    <%= hidden_field_tag "delete_translations[#{locale}]", 0 %>
     <% globalize(locale) do %>
       <%= f.text_area "description_#{locale}", rows: 5,
                       class: "js-globalize-attribute",

app/views/admin/site_customization/information_texts/_form.html.erb

@@ -2,7 +2,7 @@
 
 <%= form_tag admin_site_customization_information_texts_path do %>
   <% I18n.available_locales.each do |l| %>
-    <%= hidden_field_tag "delete_translations[#{l}]", 0 %>
+    <%= translation_enabled_tag l, site_customization_enable_translation?(l) %>
   <% end %>
   <% contents.each do |group| %>
     <% group.each do |content| %>