Start sessions of last purchase from list

Fixes #19

src/web/tracker/templates/list_sessions.html

@@ -3,13 +3,18 @@
 {% block title %}Sessions{% endblock title %}
 
 {% block content %}
-    {% if purchase %}
         <div class="text-center text-xl mb-4 dark:text-slate-400">
+            <a href="{% url 'start_session' dataset.last.purchase.id %}">
+                <button type="button" title="Track last tracked" class="py-1 px-2 bg-green-600 hover:bg-green-700 focus:ring-green-500 focus:ring-offset-blue-200 text-white transition ease-in duration-200 text-center text-base font-semibold shadow-md focus:outline-none focus:ring-2 focus:ring-offset-2 w-12 h-6 rounded-lg ">
+                    New session of {{ dataset.last.purchase }}
+                </button>
+            </a>
+            {% if purchase %}
             <h1>Listing sessions only for purchase "{{ purchase }}"</h1>
             <h2>Total playtime: {{ total_duration }} over {{ dataset.count }} sessions.</h2>
             <a class="dark:text-white hover:underline" href="{% url 'list_sessions' %}">View all sessions</a>
+            {% endif %}
         </div>
-    {% endif %}
     <div id="session-table" class="gap-4 shadow rounded-xl max-w-screen-lg mx-auto dark:bg-slate-700 p-2 justify-center">
         <div class="dark:border-white dark:text-slate-300 text-lg">Name</div>
         <div class="dark:border-white dark:text-slate-300 text-lg text-center">Start</div>