Simplify QR code generation logic

Refactored the QR code generation in `Program.cs` by using a static method `GenerateQrCode` on `QRCodeGenerator`, which eliminates the need for separate `QRCodeGenerator` and `QRCodeData` instances. This change reduces code complexity and improves performance by removing unnecessary object instantiation.

Author: marcominerva

TwoFactorAuthenticationSample/Program.cs

@@ -137,8 +137,7 @@
         Label = user.Email
     };
 
-    using var qrCodeGenerator = new QRCodeGenerator();
-    using var qrCodeData = qrCodeGenerator.CreateQrCode(payload, QRCodeGenerator.ECCLevel.Q);
+    using var qrCodeData = QRCodeGenerator.GenerateQrCode(payload, QRCodeGenerator.ECCLevel.Q);
     using var qrCode = new PngByteQRCode(qrCodeData);
 
     var qrCodeBytes = qrCode.GetGraphic(3);