feat: make it possible to enable tracking for livecode execution

Tracking of livecode execution is made possible by making the page
context with course, batch and lesson available in js.

Added a global page_context variable in js and the data for that gets
initialzied in the learn.py.

community/www/batch/learn.html

@@ -61,6 +61,11 @@
 
 {%- block script %}
 {{ super() }}
+
+<script type="text/javascript">
+  var page_context = {{ page_context | tojson }};
+</script>
+
 {% for ext in page_extensions %}
 {{ ext.render_footer() }}
 {% endfor %}