Enhanced `ExtractZugferdFromFile` and `ExtractZugferdFromBase64`
methods to support output as an XML file (`application/xml`)
or JSON (default). Introduced `asFile` and `format` query
parameters to control the output format. Updated XML
documentation and `ProducesResponseType` attributes to reflect
these changes. Default values for `CancellationToken` were
set to `default` for improved usability.
Introduced `ZugferdController` to handle ZUGFeRD-related operations, including detection and extraction of ZUGFeRD XML from PDFs via file upload or Base64-encoded payloads. Integrated `MediatR` for query/command handling.
Added `ZugferdSettings` for configurable file names and patterns, and updated `appsettings.json` and `Program.cs` to support this configuration.
Implemented `HasZugferdQuery` and `ExtractZugferdCommand` with their respective handlers and validators. Added DTOs (`ZugferdCheckResult`, `ZugferdExtractionResult`) for operation results.
Included `ZUGFeRD-Example.pdf` for testing and integrated `Serilog.Ui.Core.Extensions` for logging.
