Add the banner partial to application layout

This pulls in the user research banner partial defined in the govuk-web-banners gem.

This renders the banner in the same place on the page as was previously implemented.

app/views/layouts/application.html.erb

@@ -27,6 +27,8 @@
       <% end %>
     <% end %>
 
+    <%= render "govuk_web_banners/recruitment_banner" %>
+
     <%= yield :header %>
 
     <main role="main" id="content" class="<%= @content_item.schema_name.dasherize %>" lang="<%= I18n.locale %>">

test/integration/recruitment_banner_test.rb

@@ -24,8 +24,8 @@ class RecruitmentBannerTest < ActionDispatch::IntegrationTest
       stub_content_store_has_item(content_item["base_path"], content_item.to_json)
       visit content_item["base_path"]
 
-      assert_not page.has_css?(".gem-c-intervention")
-      assert_not page.has_link?("Sign up to take part in user research (opens in a new tab)", href: "https://survey.take-part-in-research.service.gov.uk/jfe/form/SV_2bggmg6xlelrO0S")
+      assert page.has_css?(".gem-c-intervention")
+      assert page.has_link?("Sign up to take part in user research (opens in a new tab)", href: "https://survey.take-part-in-research.service.gov.uk/jfe/form/SV_2bggmg6xlelrO0S")
     end
   end
 
@@ -47,8 +47,8 @@ class RecruitmentBannerTest < ActionDispatch::IntegrationTest
       stub_content_store_has_item(content_item["base_path"], content_item.to_json)
       visit content_item["base_path"]
 
-      assert_not page.has_css?(".gem-c-intervention")
-      assert_not page.has_link?("Sign up to take part in user research (opens in a new tab)", href: "https://survey.take-part-in-research.service.gov.uk/jfe/form/SV_2bggmg6xlelrO0S")
+      assert page.has_css?(".gem-c-intervention")
+      assert page.has_link?("Sign up to take part in user research (opens in a new tab)", href: "https://survey.take-part-in-research.service.gov.uk/jfe/form/SV_2bggmg6xlelrO0S")
     end
   end