Add missing window.toggleIndicatorExpand function

The toggleIndicatorExpand function was called in the HTML template and event listener
but was never defined. Added the function definition which toggles configuringId between
the clicked indicator ID and null, then re-renders the panel to show/hide settings.

src/api/dashboard/static/js/ui/indicators-panel-new.js

@@ -448,6 +448,11 @@ function setupEventListeners() {
 }
 
 // Actions
+window.toggleIndicatorExpand = function(id) {
+    configuringId = configuringId === id ? null : id;
+    renderIndicatorPanel();
+};
+
 window.clearSearch = function() {
     searchQuery = '';
     renderIndicatorPanel();