Enhance ExtractSwissQrCode feature documentation

Updated `DocumentEndpoints` to include detailed requirements, return values, and use case for the `ExtractSwissQrCode` endpoint.

Marked Feature 2 (`ExtractSwissQrCode`) as completed in `PHASENPLAN.md` and `ROADMAP.md`, summarizing achievements and outlining next steps for Feature 3 (`ExtractAttachments`).

Enhanced `ExtractSwissQrCodeRequest` and `ExtractSwissQrCodeResponse` DTOs with example JSON payloads for clarity.

Expanded `SwissQrCodeDataDto` and `AddressDataDto` with detailed field-level documentation to improve usability and adherence to Swiss QR Bill Standard 2.0.

DocumentOperator.Application/Common/DTOs/ExtractSwissQrCodeRequest.cs

@@ -6,6 +6,12 @@ namespace DocumentOperator.Application.Common.DTOs;
 /// </summary>
 /// <param name="References">Array of reference strings to pass through in the response</param>
 /// <param name="Base64Pdf">PDF document encoded as Base64 string</param>
+/// <example>
+/// {
+///   "references": ["REF-001", "REF-002"],
+///   "base64Pdf": "JVBERi0xLjQK..."
+/// }
+/// </example>
 public record ExtractSwissQrCodeRequest(
     IReadOnlyList<string> References,
     string Base64Pdf