refactor(AnnotationHandler): update to use System.Text.Json.JsonSerializer

EnvelopeGenerator.Domain/Constants/Format.cs

@@ -1,5 +1,9 @@
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
+#if NET
+using System.Text.Json;
+using System.Text.Json.Serialization;
+#endif
 
 namespace EnvelopeGenerator.Domain.Constants
 {
@@ -8,18 +12,22 @@ namespace EnvelopeGenerator.Domain.Constants
         #region Json Serializer Settings
         public static class Json
         {
+            //TODO: update to use System.Text.Json
             public static readonly JsonSerializerSettings ForDiagnostics = new JsonSerializerSettings()
             {
                 ContractResolver = new CamelCasePropertyNamesContractResolver(),
                 Formatting = Formatting.Indented,
                 NullValueHandling = NullValueHandling.Include
             };
-            public static readonly JsonSerializerSettings ForAnnotations = new JsonSerializerSettings()
+
+#if NET
+            public static readonly JsonSerializerOptions ForAnnotations = new()
             {
-                ContractResolver = new CamelCasePropertyNamesContractResolver(),
-                Formatting = Formatting.None,                
-                NullValueHandling = NullValueHandling.Ignore
+                PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+                WriteIndented = false,
+                DefaultIgnoreCondition = JsonIgnoreCondition.Never,
             };
+#endif
         }
         #endregion
     }