feat: Save datapanel state in local storage (#12996)

* Save datapanel state in local storage

* Export string to a constant

* Move local storage helpers to separate file

* Use helper functions in ExploreViewContainer

superset-frontend/src/utils/localStorageHelpers.ts

@@ -0,0 +1,35 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export const getFromLocalStorage = (key: string, defaultValue: any) => {
+  try {
+    const value = localStorage.getItem(key);
+    return JSON.parse(value || 'null') || defaultValue;
+  } catch {
+    return defaultValue;
+  }
+};
+
+export const setInLocalStorage = (key: string, value: any) => {
+  try {
+    localStorage.setItem(key, JSON.stringify(value));
+  } catch {
+    // Catch in case localStorage is unavailable
+  }
+};