fix: Unable to access localStorage in document embedded in iframe with third party cookies blocked (#4777)

* fix: Pasting from Microsoft Office pastes image. Closes #3058

* fix: Use Storage wrapper implementation for all editor calls to localStorage

closes #4776

shared/utils/Storage.ts

@@ -0,0 +1,95 @@
+/**
+ * Storage is a wrapper class for localStorage that allow safe usage when
+ * localStorage is not available.
+ */
+class Storage {
+  interface: typeof localStorage | MemoryStorage;
+
+  public constructor() {
+    try {
+      localStorage.setItem("test", "test");
+      localStorage.removeItem("test");
+      this.interface = localStorage;
+    } catch (_err) {
+      this.interface = new MemoryStorage();
+    }
+  }
+
+  /**
+   * Set a value in storage. For efficiency, this method will remove the
+   * value if it is undefined.
+   *
+   * @param key The key to set under.
+   * @param value The value to set
+   */
+  public set<T>(key: string, value: T) {
+    try {
+      if (value === undefined) {
+        this.remove(key);
+      } else {
+        this.interface.setItem(key, JSON.stringify(value));
+      }
+    } catch (_err) {
+      // Ignore errors
+    }
+  }
+
+  /**
+   * Get a value from storage.
+   *
+   * @param key The key to get.
+   * @param fallback The fallback value if the key doesn't exist.
+   * @returns The value or undefined if it doesn't exist.
+   */
+  public get(key: string, fallback?: any) {
+    try {
+      const value = this.interface.getItem(key);
+      if (typeof value === "string") {
+        return JSON.parse(value);
+      }
+    } catch (_err) {
+      // Ignore errors
+    }
+
+    return fallback;
+  }
+
+  /**
+   * Remove a value from storage.
+   *
+   * @param key The key to remove.
+   */
+  public remove(key: string) {
+    try {
+      this.interface.removeItem(key);
+    } catch (_err) {
+      // Ignore errors
+    }
+  }
+}
+
+/**
+ * MemoryStorage is a simple in-memory storage implementation that is used
+ * when localStorage is not available.
+ */
+class MemoryStorage {
+  private data = {};
+
+  getItem(key: string) {
+    return this.data[key] || null;
+  }
+
+  setItem(key: string, value: any) {
+    return (this.data[key] = String(value));
+  }
+
+  removeItem(key: string) {
+    return delete this.data[key];
+  }
+
+  clear() {
+    return (this.data = {});
+  }
+}
+
+export default new Storage();