Convert radios on set-template-sender page

Includes making the legend the h1 for the page to
follow design system guidance:

https://design-system.service.gov.uk/get-started/labels-legends-headings/

app/main/forms.py

@@ -2021,7 +2021,7 @@ class SetTemplateSenderForm(StripWhitespaceForm):
         self.sender.choices = kwargs['sender_choices']
         self.sender.label.text = 'Select your sender'
 
-    sender = RadioField()
+    sender = GovukRadiosField()
 
 
 class LinkOrganisationsForm(StripWhitespaceForm):

app/main/views/templates.py

@@ -829,7 +829,14 @@ def set_template_sender(service_id, template_id):
         sender=sender_details['current_choice'],
         sender_choices=sender_details['value_and_label'],
     )
-    option_hints = {sender_details['default_sender']: '(Default)'}
+    form.sender.param_extensions = {'items': []}
+    for item_value, _item_label in sender_details['value_and_label']:
+        if item_value == sender_details['default_sender']:
+            extensions = {'hint': {'text': '(Default)'}}
+        else:
+            extensions = {}  # if no extensions needed, send an empty dict to preserve order of items
+
+        form.sender.param_extensions['items'].append(extensions)
 
     if form.validate_on_submit():
         service_api_client.update_service_template_sender(
@@ -843,8 +850,7 @@ def set_template_sender(service_id, template_id):
         'views/templates/set-template-sender.html',
         form=form,
         template_id=template_id,
-        no_senders=no_senders,
+        no_senders=no_senders
-        option_hints=option_hints
     )
 
 

app/templates/views/templates/set-sender.html

@@ -1,6 +1,4 @@
 {% extends "withnav_template.html" %}
-{% from "components/radios.html" import radios %}
-{% from "components/page-header.html" import page_header %}
 {% from "components/page-footer.html" import page_footer %}
 {% from "components/form.html" import form_wrapper %}
 {% from "components/back-link/macro.njk" import govukBackLink %}

app/templates/views/templates/set-template-sender.html

@@ -1,31 +1,35 @@
 {% extends "withnav_template.html" %}
-{% from "components/radios.html" import radios %}
-{% from "components/page-header.html" import page_header %}
 {% from "components/page-footer.html" import page_footer %}
 {% from "components/form.html" import form_wrapper %}
+{% from "components/back-link/macro.njk" import govukBackLink %}
+
+{% set page_title = 'Set letter contact block' %}
 
 {% block service_page_title %}
-  Set letter contact block
+  {{ page_title }}
 {% endblock %}
 
 {% block maincolumn_content %}
 
-  {{ page_header(
+  {{ govukBackLink({ "href": url_for('.view_template', service_id=current_service.id, template_id=template_id) }) }}
-    'Set letter contact block',
+
-    back_link=url_for('.view_template', service_id=current_service.id, template_id=template_id)
+  <div class="govuk-grid-row govuk-!-margin-top-3">
-  ) }}
+    {% call form_wrapper() %}
-  <div class="govuk-grid-row">
+      {{ form.sender(param_extensions={
-    <div class="govuk-grid-column-three-quarters">
+        'fieldset': {
-      {% call form_wrapper() %}
+          'legend': {
-        {{ radios(
+            'isPageHeading': True,
-          form.sender,
+            'text': page_title,
-          option_hints=option_hints,
+            'classes': 'govuk-fieldset__legend--l govuk-grid-column-full'
-          hide_legend=True
+          }
-        ) }}
+        },
+        'classes': 'govuk-grid-column-three-quarters'
+      }) }}
+      <div class="govuk-grid-column-three-quarters">
         {{ page_footer('Continue') }}
         <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.service_add_letter_contact', service_id=current_service.id, from_template=template_id) }}">Add new sender</a>
-      {% endcall %}
     </div>
+    {% endcall %}
   </div>
 
 {% endblock %}

tests/app/main/views/test_templates.py

@@ -2527,7 +2527,7 @@ def test_add_sender_link_only_appears_on_services_with_no_senders(
         template_id=fake_uuid,
     )
 
-    assert page.select_one('.govuk-grid-column-three-quarters form > a')['href'] == url_for(
+    assert page.select_one('form .page-footer + a')['href'] == url_for(
         'main.service_add_letter_contact',
         service_id=SERVICE_ONE_ID,
         from_template=fake_uuid,