feat: Update collection overview header and remove completed state display

atlas/templates/atlas/collection_take_overview.html

@@ -16,7 +16,7 @@
                 {% if cid is not None %}
                     CID: <strong>{{ cid }}</strong>
                 {% else %}
-                    Your collection overview
+                    <h5>Overview</h5>
                 {% endif %}
             </div>
         </div>
@@ -141,7 +141,6 @@
             <div class="card-body d-flex flex-wrap justify-content-between align-items-center gap-2">
                 <div>
                     <div class="fw-semibold">Ready to submit this session?</div>
-                    <div class="small text-muted">Completed: <span id="completed-state">{{ cid_user_exam.completed }}</span></div>
                 </div>
                 <form hx-post=""
                       hx-headers='{"X-CSRFToken": "{{ csrf_token }}"}'