Add project files.

Core.Blueprint.Domain/Entities/AbsEntity.cs

@@ -0,0 +1,14 @@
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Bson;
+
+namespace Core.Blueprint.Domain.Entities
+{
+    public abstract class AbsEntity
+    {
+        [BsonId]
+        [BsonRepresentation(BsonType.ObjectId)]
+        [BsonElement("_id")]
+        public string? Id { get; set; }
+        public char StatusCode { get; set; } = 'P';
+    }
+}