Fix duplicated H1 on ‘New letter branding’ page

For accessibility reasons a page should have one (and only one) H1. This
commit fixes an instance where the H1 was duplicated as a result of the
work done to componentize our page headings.

It also adds an extra check to `client_request` so that we don’t
introduce pages with multiple or no H1s in the future.

app/templates/components/folder-path.html

@@ -3,9 +3,10 @@
   service_id,
   template_type,
   current_user,
-  link_current_item=False
+  link_current_item=False,
+  root_element='h1'
 ) %}
-  <h1 class="heading-medium folder-heading">
+  <{{ root_element }} class="heading-medium folder-heading">
     {% for folder in folders %}
       {% if loop.last and not link_current_item %}
         {% if folder.template_type or not folder.id %}
@@ -26,7 +27,7 @@
         {% if not loop.last %}{{ folder_path_separator() }}{% endif %}
       {% endif %}
     {% endfor %}
-  </h1>
+  </{{ root_element }}>
 {% endmacro %}
 
 

app/templates/views/letter-branding/manage-letter-branding.html

@@ -11,7 +11,6 @@
 
 {% block platform_admin_content %}
 
-  <h1 class="heading-large">{{ '{} letter branding'.format('Update' if is_update else 'Add')}}</h1>
   {{ page_header(
     '{} letter branding'.format('Update' if is_update else 'Add'),
     back_link=url_for('main.letter_branding')

app/templates/views/templates/choose-reply.html

@@ -14,7 +14,7 @@
 
 <div class="bottom-gutter-1-2">
   <h1 class="heading-large">Choose a template</h1>
-  {{ folder_path(template_folder_path, current_service.id, template_type, current_user) }}
+  {{ folder_path(template_folder_path, current_service.id, template_type, current_user, root_element='h2') }}
 </div>
 
   {% if not templates_and_folders.templates_to_show %}