Make all WM elements inherit from common templates

core/templates/modals/drilldown.html

@@ -1,13 +1,5 @@
-{% load index %}
-{% load static %}
+{% extends 'wm/modal.html' %}
 
-<script src="{% static 'modal.js' %}"></script>
-<div id="modal" class="modal is-active is-clipped">
-  <div class="modal-background"></div>
-  <div class="modal-content">
-    <div class="box">
-      {% include 'window-content/drilldown.html' %}
-      <button class="modal-close is-large" aria-label="close"></button>
-    </div>
-  </div>
-</div>
+{% block modal_content %}
+  {% include 'window-content/drilldown.html' %}
+{% endblock %}