replace slippers with django-cotton

main reason: slippers cannot pass request via context inside its
components, making it annoying to use template takes that take request.
more reasons: not actively worked on, no named slots, having to define
components in components.yaml + new components do not get registered
without restarting server

games/templates/cotton/table.html

@@ -0,0 +1,12 @@
+<div class="relative overflow-x-auto shadow-md sm:rounded-lg">
+    <table class="w-full text-sm text-left rtl:text-right text-gray-500 dark:text-gray-400">
+        <thead class="text-xs text-gray-700 uppercase bg-gray-50 dark:bg-gray-700 dark:text-gray-400">
+            <tr>
+                {% for column in columns %}<th scope="col" class="px-6 py-3">{{ column }}</th>{% endfor %}
+            </tr>
+        </thead>
+        <tbody>
+            {{ slot }}
+        </tbody>
+    </table>
+</div>