Add live search to letter brandings

Matches what we do for email branding, makes the one you’re lookig for
quicker to find.

app/main/views/service_settings.py

@@ -891,6 +891,7 @@ def set_letter_branding(service_id):
     return render_template(
         'views/service-settings/set-letter-branding.html',
         form=form,
+        search_form=SearchTemplatesForm(),
     )
 
 

app/templates/views/service-settings/set-letter-branding.html

@@ -1,5 +1,6 @@
 {% extends "withnav_template.html" %}
 {% from "components/radios.html" import radios %}
+{% from "components/live-search.html" import live_search %}
 {% from "components/page-footer.html" import page_footer %}
 {% from "components/form.html" import form_wrapper %}
 
@@ -10,17 +11,14 @@
 {% block maincolumn_content %}
 
   <h1 class="heading-large">Set letter branding</h1>
-  <div class="grid-row">
-    <div class="column-three-quarters">
-      {% call form_wrapper() %}
-        {{ radios(form.dvla_org_id) }}
-        {{ page_footer(
-          'Save',
-          back_link=url_for('.service_settings', service_id=current_service.id),
-          back_link_text='Back to settings'
-        ) }}
-      {% endcall %}
-    </div>
-  </div>
+  {% call form_wrapper() %}
+    {{ live_search(target_selector='.multiple-choice', show=True, form=search_form, label='Search by name') }}
+    {{ radios(form.dvla_org_id) }}
+    {{ page_footer(
+      'Save',
+      back_link=url_for('.service_settings', service_id=current_service.id),
+      back_link_text='Back to settings'
+    ) }}
+  {% endcall %}
 
 {% endblock %}