feat(FinishEnvelopeJob): enhance FinishEnvelopeJob to fetch signed envelopes

- Added MediatR dependency to query envelopes
- Injected GdPictureOptions via IOptions
- Updated Execute method to fetch envelopes with status 'EnvelopeCompletelySigned'
- Preserved logging with job details
- Prepared loop for further processing of envelopes

EnvelopeGenerator.Application/Envelopes/Queries/ReadEnvelopeQuery.cs

@@ -1,18 +1,24 @@
 using MediatR;
 using EnvelopeGenerator.Domain.Constants;
 using EnvelopeGenerator.Application.Common.Query;
+using EnvelopeGenerator.Application.Common.Dto;
 
 namespace EnvelopeGenerator.Application.Envelopes.Queries;
 
 /// <summary>
 /// Repräsentiert eine Abfrage für Umschläge.
 /// </summary>
-public record ReadEnvelopeQuery : EnvelopeQueryBase, IRequest
+public record ReadEnvelopeQuery : EnvelopeQueryBase, IRequest<IEnumerable<EnvelopeDto>>
 {
     /// <summary>
     /// Abfrage des Include des Umschlags
     /// </summary>
     public EnvelopeStatusQuery? Status { get; init; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public bool? HasDocResult { get; init; }
 }
 
 /// <summary>