ui: add template for csrf errors

passbook/core/templates/403_csrf.html

@@ -0,0 +1,27 @@
+{% extends 'login/base.html' %}
+
+{% load static %}
+{% load i18n %}
+{% load utils %}
+
+{% block card_title %}
+{{ title }} <span>(403)</span>
+{% endblock %}
+
+{% block card %}
+<form>
+    <h3>{{ main }}</h3>
+    {% if no_referer %}
+    <p>{{ no_referer1 }}</p>
+    <p>{{ no_referer2 }}</p>
+    <p>{{ no_referer3 }}</p>
+    {% endif %}
+    {% if no_cookie %}
+    <p>{{ no_cookie1 }}</p>
+    <p>{{ no_cookie2 }}</p>
+    {% endif %}
+    {% if 'back' in request.GET %}
+    <a href="{% back %}" class="btn btn-primary btn-block btn-lg">{% trans 'Back' %}</a>
+    {% endif %}
+</form>
+{% endblock %}