Add testing for validation

Core/Validation/ValidationConfiguration.cs

@@ -148,7 +148,12 @@ public class ValidationConfiguration
     {
         try
         {
-            return JsonSerializer.Deserialize<ValidationConfiguration>(json) ?? Default;
+            var options = new JsonSerializerOptions
+            {
+                PropertyNameCaseInsensitive = true,
+                Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() }
+            };
+            return JsonSerializer.Deserialize<ValidationConfiguration>(json, options) ?? Default;
         }
         catch
         {
@@ -183,10 +188,12 @@ public class ValidationConfiguration
     /// <param name="path">Path where the JSON file should be saved</param>
     public async Task SaveToFileAsync(string path)
     {
-        var json = JsonSerializer.Serialize(this, new JsonSerializerOptions
+        var options = new JsonSerializerOptions
         {
-            WriteIndented = true
-        });
+            WriteIndented = true,
+            Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() }
+        };
+        var json = JsonSerializer.Serialize(this, options);
         await File.WriteAllTextAsync(path, json);
     }
 }