Reconfigure HTML publication titles

- adjust options on inverse header following change, setting padding and use subtext in place of hard coded para and application level styles
- replace title component with heading component

app/assets/stylesheets/views/_html-publication.scss

@@ -11,11 +11,6 @@
     }
   }
 
-  .publication-header__last-changed {
-    margin-top: govuk-spacing(3);
-    @include govuk-font(19);
-  }
-
   .contents-list-container {
     @include govuk-media-query($from: desktop) {
       position: sticky;

app/views/content_items/html_publication.html.erb

@@ -23,15 +23,18 @@
   </div>
 <% end %>
 
-<%= render 'govuk_publishing_components/components/inverse_header', {} do %>
-  <%= render 'govuk_publishing_components/components/title',
-        title: @content_item.title,
-        context: I18n.t("content_item.schema_name.#{@content_item.format_sub_type}", count: 1),
-        inverse: true,
-        margin_bottom: 0,
-        margin_top: 3
-  %>
-  <p class="publication-header__last-changed"><%= @content_item.last_changed %></p>
+<%= render 'govuk_publishing_components/components/inverse_header', {
+  padding_top: 6,
+  padding_bottom: 6,
+  subtext: @content_item.last_changed
+} do %>
+  <%= render "govuk_publishing_components/components/heading", {
+    text: @content_item.title,
+    context: I18n.t("content_item.schema_name.#{@content_item.format_sub_type}", count: 1),
+    inverse: true,
+    margin_bottom: 0,
+    font_size: "xl",
+  } %>
 <% end %>
 
 <%= render 'shared/history_notice', content_item: @content_item %>