Refactor EnvelopeDto and improve response handling

Updated the `EnvelopeDto` class by removing several properties to simplify the data structure and added `AddedWhen`, `ChangedWhen`, and a nullable `EnvelopeType`.

Modified the return statement in `EnvelopeController.cs` to return `NotFound()` when no envelopes are present, enhancing the accuracy of HTTP responses.

EnvelopeGenerator.Application/DTOs/EnvelopeDto.cs

@@ -21,9 +21,9 @@ namespace EnvelopeGenerator.Application.DTOs
 
 		[TemplatePlaceholder("[MESSAGE]")]
 		public string Message { get; set; }
-		public DateTime? ExpiresWhen { get; set; }
-		public DateTime? ExpiresWarningWhen { get; set; }
+
 		public DateTime AddedWhen { get; set; }
+
 		public DateTime? ChangedWhen { get; set; }
 
 		[TemplatePlaceholder("[DOCUMENT_TITLE]")]
@@ -33,40 +33,22 @@ namespace EnvelopeGenerator.Application.DTOs
 
 		public string Language { get; set; }
 
-		public bool? SendReminderEmails { get; set; }
-
-		public int? FirstReminderDays { get; set; }
-
-		public int? ReminderIntervalDays { get; set; }
-
 		public int? EnvelopeTypeId { get; set; }
 
 		public int? CertificationType { get; set; }
 
 		public bool? UseAccessCode { get; set; }
 
-		public int? FinalEmailToCreator { get; set; }
-
-		public int? FinalEmailToReceivers { get; set; }
-
-		public int? ExpiresWhenDays { get; set; }
-
-		public int? ExpiresWarningWhenDays { get; set; }
-
         public bool TFAEnabled { get; init; }
 
-        public bool DmzMoved { get; set; }
 		public UserReadDto? User { get; set; }
+
 		public EnvelopeType? EnvelopeType { get; set; }
 
 		public string? EnvelopeTypeTitle { get; set; }
 
 		public bool IsAlreadySent { get; set; }
 
-		public string? StatusTranslated { get; set; }
-
-		public string? ContractTypeTranslated { get; set; }
-
         public byte[]? DocResult { get; init; }
 
         public IEnumerable<EnvelopeDocumentDto>? Documents { get; set; }