Add a page to pick a template to reply with

If your service is receiving inbound messages, you might want to reply
to them. Without an API integration, the only way to do this is by doing
the send one off flow. But currently there is no direct link from the
page which shows the inbound messages.

So this commit:
- adds a link to a new page…
- …which shows the available (ie only text message) templates with which
  you can reply

app/templates/views/conversations/conversation.html

@@ -22,6 +22,12 @@
       'messages',
     ) }}
 
+    {% if current_user.has_permissions(['send_texts'], admin_override=True) %}
+      <p>
+        <a href="{{ url_for('.conversation_reply', service_id=current_service.id, notification_id=notification_id) }}">Send a text message to this phone number</a>
+      </p>
+    {% endif %}
+
   </div>
 
 {% endblock %}

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

@@ -0,0 +1,56 @@
+{% from "components/pill.html" import pill %}
+{% from "components/message-count-label.html" import message_count_label %}
+{% from "components/textbox.html" import textbox %}
+
+{% extends "withnav_template.html" %}
+
+{% block service_page_title %}
+  Choose a template
+{% endblock %}
+
+{% block maincolumn_content %}
+
+  <h1 class="heading-large">Choose a template</h1>
+
+  {% if not templates %}
+
+    {% if current_user.has_permissions(permissions=['manage_templates'], any_=True) %}
+       <p class="bottom-gutter">
+         You need a template before you can send text messages.
+       </p>
+      <a href="{{ url_for('.add_template_by_type', service_id=current_service.id) }}" class="button">Add a new template</a>
+    {% else %}
+      <p>
+        You need to ask your service manager to add templates before you
+        can send text messages.
+      </p>
+    {% endif %}
+
+  {% else %}
+
+    {% if show_search_box %}
+      <div data-module="autofocus">
+        <div class="live-search" data-module="live-search" data-targets="#template-list .column-whole">
+          {{ textbox(
+            search_form.search,
+            width='1-1'
+          ) }}
+        </div>
+      </div>
+    {% endif %}
+
+    <nav class="grid-row" id=template-list>
+      {% for template in templates %}
+        <div class="column-whole">
+          <h2 class="message-name">
+            <a href="{{ url_for('.view_template', service_id=current_service.id, template_id=template.id) }}">{{ template.name }}</a>
+          </h2>
+          <p class="message-type">
+            {{ message_count_label(1, template.template_type, suffix='')|capitalize }} template
+          </p>
+        </div>
+      {% endfor %}
+    </nav>
+  {% endif %}
+
+{% endblock %}