Add Two-Factor Authentication (2FA) with Authenticator App Support in Blazor WebAssembly

[neozhu]

Summary

This pull request introduces the implementation of Two-Factor Authentication (2FA) in the Blazor WebAssembly application, leveraging authenticator apps such as Google Authenticator or Microsoft Authenticator. The changes enhance security by requiring an additional layer of verification for user authentication.

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Key Features

1. Enable 2FA for Users:

   • Backend generates a TOTP secret (authenticatorKey) and returns a QR code URI.
   • Frontend displays the QR code for users to scan with their authenticator app.

2. Verify 2FA Setup:

   • Users verify the 2FA setup by entering a code generated by their authenticator app.
   • Successful verification enables 2FA for the user's account.

3. Login with 2FA:

   • If 2FA is enabled, users are prompted to enter their 2FA code during login.
   • Supports both TOTP codes and recovery codes for flexible authentication.

4. Improved User Feedback:

   • Snackbar notifications are used to provide clear feedback for both successful and failed operations.
   • Example feedback includes "Two-factor authentication enabled successfully" and "Invalid verification code."

[neozhu]

[neozhu]

add GenerateRecoveryCodes