This pull request introduces a comprehensive implementation of a Native Authentication sample app using the Microsoft Authentication Library (MSAL) for JavaScript. The changes include detailed documentation, new core classes, and expanded functionality for authentication flows like sign-in, sign-up, and password reset.

Documentation Enhancements:

• Added a new README.md for the Native Auth Sample, detailing authentication flows, project structure, key components, and end-to-end test cases. This includes configurations for email/password, email/OTP, and redirect-based flows, along with both positive and negative test scenarios.

Core Functionality:

• Introduced the NativeAuthApp class in app.js as the main entry point for the application. It initializes the MSAL instance, handles navigation between forms, and provides methods for sign-in, sign-up, and password reset flows.

User Attribute Management:

• Added the UserAccountAttributes class in UserAccountAttributes.js to manage custom user attributes like first name, last name, and display name. This supports the sign-up flow with customizable attributes.