fix: allow collapsing a SideNav menu when it is not active

It should be possible to collapse a parent item regardless of whether
or not it is the currently active item.  Prior to this fix, clicking
on a parent item's "fold" icon was ignored unless the item was the
currently active one.  With this fix, the parent node and its children
will be collapsed, as expected.

src/components/SideMenu/SideMenu.tsx

@@ -38,8 +38,12 @@ export class SideMenu extends React.Component<{ menu: MenuStore; className?: str
   }
 
   activate = (item: IMenuItem) => {
-    if (item && item.active && this.context.menuToggle) {
-      return item.expanded ? item.collapse() : item.expand();
+    if (item && this.context.menuToggle) {
+      if (item.expanded) {
+        item.collapse();
+        return;
+      }
+      if (item.active) item.expand();
     }
     this.props.menu.activateAndScroll(item, true);
     setTimeout(() => {