restore base.html as it has been removed from publik-base-theme (#25154)

templates/base.html

@@ -0,0 +1,33 @@
+{% extends theme_base %}
+
+{% block extra-body-args %}
+{% block bodyargs %}
+{% endblock %}
+{% endblock %}
+
+{% block placeholder-content %}
+  {% block content %}
+  {% endblock %}
+{% endblock %}
+
+{% block user-info %}
+          {% if user.is_authenticated %}
+          <span class="logged-in">
+            {% if idp_account_url %}<a href="{{idp_account_url}}">{% endif %}
+            <span class="connected-user">{{user.first_name}} {{user.last_name}}</span>{% if idp_account_url %}</a>{% endif %}
+            <a class="logout" href="{% url 'auth_logout' %}">D&eacute;connexion</a>
+          </span>
+          {% endif %}
+{% endblock %}
+
+{% block messages %}
+{% if messages %}
+  <div id="messages" class="messages-login">
+    <ul class="messages">
+      {% for message in messages %}
+      <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
+      {% endfor %}
+    </ul>
+  </div>
+{% endif %}
+{% endblock %}