Update h1 on pill pages to work with new pill

Pill pages are:
- /notifications
- /template-usage
- /monthly
- /organisations/<organisation_id>
- /templates

Includes changes to:
- the folder-path component
- the page-header component

...all their h1s have the same id.

app/templates/views/templates/choose.html

@@ -4,6 +4,7 @@
 {% from "components/textbox.html" import textbox %}
 {% from "components/live-search.html" import live_search %}
 {% from "components/form.html" import form_wrapper %}
+{% from "components/page-header.html" import page_header %}
 {% from "components/page-footer.html" import page_footer %}
 
 {% extends "withnav_template.html" %}
@@ -18,9 +19,7 @@
 
   {% if (not current_service.all_templates) and (not current_service.all_template_folders) %}
 
-    <h1 class="heading-medium">
-      {{ page_title }}
-    </h1>
+     {{ page_header(page_title, size='medium') }}
 
      <p class="govuk-body">
        {% if current_user.has_permissions('manage_templates') %}