Add DateHelper and add new method in LocaleHelper

- Add new DateHelper to deal with the last updated date on help pages
- Add page_text_direction to LocaleHelper

Commit audit trail:
- app/helpers/locale_helper.rb https://github.com/alphagov/government-frontend/blob/af54031948650448b965ac274c3248d23658c4f6/app/helpers/application_helper.rb
- app/helpers/date_helper.rb https://github.com/alphagov/government-frontend/blob/af54031948650448b965ac274c3248d23658c4f6/app/presenters/content_item_presenter.rb

app/helpers/date_helper.rb

@@ -0,0 +1,5 @@
+module DateHelper
+  def display_date(timestamp, format = "%-d %B %Y")
+    I18n.l(Time.zone.parse(timestamp), format:, locale: "en") if timestamp
+  end
+end

app/helpers/locale_helper.rb

@@ -2,4 +2,8 @@ module LocaleHelper
   def lang_attribute(locale)
     "lang=#{locale}" unless I18n.default_locale.to_s == locale.to_s
   end
+
+  def page_text_direction
+    I18n.t("i18n.direction", locale: I18n.locale, default: "ltr")
+  end
 end

spec/helpers/date_helper_spec.rb

@@ -0,0 +1,15 @@
+RSpec.describe DateHelper do
+  include DateHelper
+
+  let(:timestamp) { "2024-10-03 19:30:22 +0100" }
+
+  describe "#display_date" do
+    it "returns a formatted date" do
+      expect(display_date(timestamp)).to eq("3 October 2024")
+    end
+
+    it "returns nil if passed nil" do
+      expect(display_date(nil)).to be_nil
+    end
+  end
+end