Update imports from Fernet module

src/core/operations/FernetDecrypt.mjs

@@ -4,8 +4,8 @@
  * @license Apache-2.0
  */
 
-import Operation from "../Operation";
-import OperationError from "../errors/OperationError";
+import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
 import fernet from "fernet";
 
 /**