Replaced the fully qualified reference to
`DocumentService.Application.Common.DTOs.PdfValidationResult.IsValid`
with the simpler `PdfValidationResult.IsValid`.
Added a `TryExtract` method to the `SwissQrCodeResult` record to
improve code readability and usability. The method follows the
standard `TryXxx` pattern, allowing for an `if/else` branch
instead of a direct null-check on the `QrCode` property. It
returns `true` if the PDF was valid and a Swiss QR Code was
successfully extracted, and `false` otherwise.
Refactored `ExtractSwissQrCodeAsync` to `InspectSwissQrCodeAsync`, introducing `SwissQrCodeResult` to encapsulate both validation and extraction results. Removed `throwIfInvalid` parameter, ensuring validation details are always returned without exceptions. Added extension methods for file path handling to improve usability.
Updated tests to reflect the new behavior, ensuring extraction is never attempted on invalid documents and validation results are always populated. Simplified API surface by removing redundant overloads and improving stream handling. Enhanced documentation and performed general code cleanup for better maintainability.
