Refactor DTOs for improved structure and documentation

Transitioned from records to classes for flexibility, added XML documentation for clarity, and updated property definitions to use standard getters and setters. Introduced the `required` keyword for essential properties, removed unnecessary constructors, and enhanced property descriptions for better readability. Additionally, overridden `GetHashCode` in `ReceiverReadDto` for proper collection behavior.

EnvelopeGenerator.Application/DTOs/Receiver/ReceiverReadDto.cs

@@ -1,5 +1,4 @@
 using DigitalData.Core.Abstractions;
-using DigitalData.Core.DTO;
 using EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
 using Microsoft.AspNetCore.Mvc;
 using System.Text.Json.Serialization;
@@ -7,19 +6,27 @@ using System.Text.Json.Serialization;
 namespace EnvelopeGenerator.Application.DTOs.Receiver;
 
 [ApiExplorerSettings(IgnoreApi = true)]
-public record ReceiverReadDto(
-    int Id,
-    string EmailAddress,
-    string Signature,
-    DateTime AddedWhen
-    ) : BaseDTO<int>(Id), IUnique<int>
+public class ReceiverReadDto : IUnique<int>
 {
+    public int Id { get; set; }
+
+    public string EmailAddress { get; set; }
+
+    public string Signature { get; set; }
+
+    public DateTime AddedWhen { get; set; }
+
     [JsonIgnore]
-    public IEnumerable<EnvelopeReceiverBasicDto>? EnvelopeReceivers { get; init; }
+    public IEnumerable<EnvelopeReceiverBasicDto>? EnvelopeReceivers { get; set; }
 
     public string? LastUsedName => EnvelopeReceivers?.LastOrDefault()?.Name;
 
     public string? TotpSecretkey { get; set; } = null;
 
     public DateTime? TfaRegDeadline { get; set; }
-};
+
+    public override int GetHashCode()
+    {
+        return Id.GetHashCode();
+    }
+}