WebUI: Improve folder collapse behavior

When the left arrow key is triggered while on a file or collapsed folder, we now select the parent folder.

Author: Piccirello

src/webui/www/private/scripts/dynamicTable.js

@@ -2460,11 +2460,22 @@ window.qBittorrent.DynamicTable ??= (() => {
                 return;
 
             const node = this.getNode(id);
-            if (node.isFolder) {
+            if (node.isFolder && !this.isCollapsed(node.rowId)) {
                 this.collapseNode(node.rowId);
                 if (this.useVirtualList)
                     this.rerender();
+                return;
             }
+
+            // when node is already collapsed or is a file, select parent
+            const parent = node.root;
+            if ((parent === null) || (parent.rowId === null))
+                return;
+
+            const parentRowId = parent.rowId.toString();
+            this.deselectAll();
+            this.selectRow(parentRowId);
+            this.getTrByRowId(parentRowId)?.focus({ preventScroll: true });
         }
 
         isAllCheckboxesChecked() {