Refactor envelope and user query structures

- Introduced a new `UserQuery` record to encapsulate user-related information, replacing individual fields in `EnvelopeQuery`.
- Added a `ReferenceType` property in `EnvelopeHistoryQuery` to enhance reference handling logic.
- Modified `EnvelopeQuery` to use the new `UserQuery` structure, simplifying the data model.
- Updated `HistoryController` with a new constructor and restructured the `GetReferenceTypes` method.
- Introduced `ReadEnvelopeHistoryQuery` to allow for more specific envelope history queries.
- Overall improvements enhance code structure, clarity, and querying capabilities.

EnvelopeGenerator.Application/EnvelopeHistories/EnvelopeHistoryQuery.cs

@@ -1,5 +1,6 @@
 using EnvelopeGenerator.Application.Envelopes;
 using EnvelopeGenerator.Application.Receivers;
+using static EnvelopeGenerator.Common.Constants;
 
 namespace EnvelopeGenerator.Application.EnvelopeHistories;
 
@@ -13,4 +14,10 @@ public record EnvelopeHistoryQuery<TEnvelopeQuery, TReceiverQuery>(int EnvelopeI
     where TEnvelopeQuery : EnvelopeQuery
     where TReceiverQuery : ReceiverQuery
 {
+    public ReferenceType ReferenceType => 
+        Envelope?.User is not null 
+            ? ReferenceType.Receiver 
+            : Receiver is not null 
+                ? ReferenceType.Receiver 
+                : ReferenceType.System;
 }

EnvelopeGenerator.Application/EnvelopeHistories/Queries/Read/ReadEnvelopeHistoryQuery.cs

@@ -0,0 +1,17 @@
+using EnvelopeGenerator.Application.Envelopes.Queries.Read;
+using EnvelopeGenerator.Application.Receivers.Queries.Read;
+
+namespace EnvelopeGenerator.Application.EnvelopeHistories.Queries.Read;
+
+/// <summary>
+/// Repräsentiert eine Abfrage für die Verlaufshistorie eines Umschlags.
+/// </summary>
+/// <param name="EnvelopeId">Die eindeutige Kennung des Umschlags.</param>
+/// <param name="Envelope">Die Abfrage, die den Umschlag beschreibt.</param>
+/// <param name="Receiver">Die Abfrage, die den Empfänger beschreibt.</param>
+public record ReadEnvelopeHistoryQuery(
+    int EnvelopeId,
+    ReadEnvelopeQuery? Envelope,
+    ReadReceiverQuery? Receiver,
+    StatusQuery? Status)
+    : EnvelopeHistoryQuery<ReadEnvelopeQuery, ReadReceiverQuery>(EnvelopeId, Envelope, Receiver, Status);