Add option to copy existing template when adding

Sometimes when setting up a service you might have a few very similar
templates, in which only a small amount of content. Or you might even
have a few of services, which are used by different teams but have
similar templates.

Copy and pasting, especially from one service to another, is a pain.
This commit makes it easier by allowing users to copy an existing
template when choosing to add a new one, instead of starting from
scratch.

app/templates/views/edit-email-template.html

@@ -13,7 +13,10 @@
       {{ heading_action }} email template
     </h1>
 
-    <form method="post">
+    <form
+      method="post"
+      action="{{ url_for('.add_service_template', service_id=current_service.id, template_type=template_type) }}"
+    >
       <div class="grid-row">
         <div class="column-five-sixths">
           {{ textbox(form.name, width='1-1', hint='Your recipients won’t see this', rows=10) }}

app/templates/views/edit-letter-template.html

@@ -12,7 +12,10 @@
       {{ heading_action }} letter template
     </h1>
 
-    <form method="post">
+    <form
+      method="post"
+      action="{{ url_for('.add_service_template', service_id=current_service.id, template_type=template_type) }}"
+    >
       <div class="grid-row">
         <div class="column-five-sixths">
           {{ textbox(form.name, width='1-1', hint='Your recipients won’t see this', rows=10) }}

app/templates/views/edit-sms-template.html

@@ -13,7 +13,10 @@
       {{ heading_action }} text message template
     </h1>
 
-    <form method="post">
+    <form
+      method="post"
+      action="{{ url_for('.add_service_template', service_id=current_service.id, template_type=template_type) }}"
+    >
       <div class="grid-row">
         <div class="column-two-thirds">
           {{ textbox(form.name, width='1-1', hint='Your recipients won’t see this') }}

app/templates/views/templates/copy.html

@@ -0,0 +1,36 @@
+{% from "components/message-count-label.html" import message_count_label %}
+
+{% extends "withnav_template.html" %}
+
+{% block service_page_title %}
+  Copy an existing template
+{% endblock %}
+
+{% block maincolumn_content %}
+
+    <div class="bottom-gutter-3-2">
+      <h1 class="heading-large">Copy an existing template</h1>
+    </div>
+    <nav>
+      {% for service in services %}
+        {% if service.templates and services|length > 1 %}
+          <h2 class="">
+            {{ service.name }}
+          </h2>
+          <div class="left-gutter-4-3 bottom-gutter-3-2">
+        {% endif %}
+        {% for template in service.templates %}
+          <h2 class="message-name">
+            <a href="{{ url_for('.copy_template', service_id=current_service.id, template_id=template.id, from_service=service.id) }}">{{ template.name }}</a>
+          </h2>
+          <p class="message-type">
+            {{ message_count_label(1, template.template_type, suffix='')|capitalize }} template
+          </p>
+        {% endfor %}
+        {% if service.templates %}
+          </div>
+        {% endif %}
+      {% endfor %}
+    </nav>
+
+{% endblock %}