Add Receivers property to EnvelopeDto

Enhanced the EnvelopeDto class by introducing a new `Receivers` property of type `IEnumerable<ReceiverDto>?` to support including recipient information in the envelope DTO.

Added necessary `using` directives for `EnvelopeReceiver` and `Receiver` DTOs to ensure proper namespace references. Updated the class to accommodate this new functionality.

EnvelopeGenerator.Application/Common/Dto/EnvelopeDto.cs

@@ -1,9 +1,12 @@
 using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
 using DigitalData.UserManager.Application.DTOs.User;
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
 using EnvelopeGenerator.Domain.Constants;
 using EnvelopeGenerator.Domain.Entities;
 using EnvelopeGenerator.Domain.Interfaces;
 using Microsoft.AspNetCore.Mvc;
+using System.Text.Json.Serialization;
 
 namespace EnvelopeGenerator.Application.Common.Dto;
 
@@ -126,4 +129,9 @@ public record EnvelopeDto : IEnvelope
     /// 
     /// </summary>
     public IEnumerable<DocumentDto>? Documents { get; set; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public IEnumerable<ReceiverDto>? Receivers { get; set; }
 }