Refactor enum usage in codebase

Updated references from `Constants` to direct usage of `EnvelopeStatus` and `EmailTemplateType` enums. This change enhances code readability and reduces dependency on the `Constants` class.

Modified properties and parameters across command classes, DTOs, repositories, and services to use the enums directly. Updated `ModifyDocStatusCommandBase`, `EnvelopeHistoryDto`, and `ResetEmailTemplateCommand` for improved clarity.

Consistent updates across multiple files indicate a systematic refactoring aimed at streamlining the codebase and improving maintainability. Comments and documentation have also been revised to reflect these changes.

EnvelopeGenerator.Domain/Entities/Envelope.cs

@@ -1,6 +1,8 @@
 using DigitalData.UserManager.Domain.Entities;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
+using EnvelopeGenerator.Domain.Constants;
+
 #if NETFRAMEWORK
 using System;
 using System.Collections.Generic;
@@ -22,7 +24,7 @@ public class Envelope
         // TODO: * Check the Form App and remove the default value
 #if NETFRAMEWORK
         Id = 0;
-        Status = Constants.EnvelopeStatus.EnvelopeCreated;
+        Status = EnvelopeStatus.EnvelopeCreated;
         Uuid = Guid.NewGuid().ToString();
         Message = My.Resources.Envelope.Please_read_and_sign_this_document;
         Title= string.Empty;
@@ -50,7 +52,7 @@ public class Envelope
 
     [Required]
     [Column("STATUS")]
-    public Constants.EnvelopeStatus Status { get; set; }
+    public EnvelopeStatus Status { get; set; }
 
     [Required]
     [Column("ENVELOPE_UUID", TypeName = "nvarchar(36)")]
@@ -153,7 +155,7 @@ public class Envelope
     public string CURRENT_WORK_APP { get; set; } = "signFLOW GUI";
 
     [NotMapped]
-    public bool IsAlreadySent => Status > Constants.EnvelopeStatus.EnvelopeSaved;
+    public bool IsAlreadySent => Status > EnvelopeStatus.EnvelopeSaved;
 #endif
 
     public List<EnvelopeDocument> Documents { get; set; }

EnvelopeGenerator.Domain/Entities/EnvelopeHistory.cs

@@ -32,7 +32,7 @@ public class EnvelopeHistory : IHasEnvelope, IHasReceiver
 
     [Required]
     [Column("STATUS")]
-    public Constants.EnvelopeStatus  Status { get; set; }
+    public EnvelopeStatus  Status { get; set; }
 
     [Required]
     [Column("ADDED_WHEN", TypeName = "datetime")]