feat(templates/shared): update navbar client link functionality

- **New Features**
  - Added dynamic URL reference for the client list page using `{% url 'client_list' %}` in the navbar.

- **Enhancements & Refinements**
  - Improved user navigation experience by replacing a static placeholder link with a functional client list page URL.

templates/shared/navbar.html

@@ -38,7 +38,7 @@
                     </a>
                 </li>
                 <li>
-                    <a href="#"
+                    <a href="{% url 'client_list' %}"
                         class="flex items-center py-2 px-3 text-heading rounded hover:bg-neutral-tertiary md:hover:bg-transparent md:hover:text-fg-brand md:p-0 md:dark:hover:bg-transparent transition-colors duration-200">
                         <svg class="w-5 h-5 me-2" aria-hidden="true" xmlns="http://www.w3.org/2000/svg" width="24"
                             height="24" fill="none" viewBox="0 0 24 24">