Refactor filter panels and enhance sidebar functionality

- Updated filter panel toggle icons from chevron-up to chevron-down across multiple pages for consistency.
- Added 'collapsed' class to filter content divs to manage visibility state.
- Enhanced library page button for tidying up media items, replacing the trash icon with a custom SVG broom icon.
- Improved CSS styles for sidebar and page header to ensure visibility and proper layout when the sidebar is collapsed.
- Introduced JavaScript functionality to manage sidebar width and state, including theme toggle for light/dark mode.
- Created a new notification drawer template that adapts based on the compact view state.

custom/otssignange/views/authed-sidebar.twig

@@ -11,7 +11,10 @@
             </span>
             <span class="brand-text">OTS Signs</span>
         </a>
-        <button class="sidebar-collapse-btn" type="button" aria-label="{% trans "Collapse sidebar" %}">
+        <button class="sidebar-expand-btn" type="button" aria-label="{% trans "Expand sidebar" %}">
+            <i class="fa fa-chevron-right" aria-hidden="true"></i>
+        </button>
+        <button class="sidebar-collapse-btn sidebar-collapse-btn-visible" type="button" aria-label="{% trans "Collapse sidebar" %}">
             <i class="fa fa-chevron-left" aria-hidden="true"></i>
         </button>
     </div>