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/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")]