This commit implements a complete rebranding of the project:
- Updated all namespaces from `DocumentOperator` to `DocumentService`.
- Renamed file paths, embedded resources, and test data references.
- Updated configuration keys, logging paths, and Redis instance names.
- Revised documentation to reflect the new project name.
- Modified project and solution files to align with the new structure.
- Updated class names, DTOs, commands, queries, and handlers.
- Adjusted middleware, controllers, and API endpoints.
- Updated Swagger metadata and API titles to `DocumentService API`.
- Refactored test namespaces, resource paths, and embedded resources.
- Updated build and deployment configurations for the new name.
- Replaced all references to `DocumentOperator` in comments and literals.
These changes ensure consistency across the codebase and documentation.
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.
