Introduce IContentNestedDataSerializer to allow injecting a custom serializer for nucache

src/Umbraco.Web/PublishedCache/NuCache/DataSource/JsonContentNestedDataSerializer.cs

@@ -0,0 +1,31 @@
+using Newtonsoft.Json;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Umbraco.Core.Serialization;
+
+namespace Umbraco.Web.PublishedCache.NuCache.DataSource
+{
+    internal class JsonContentNestedDataSerializer : IContentNestedDataSerializer
+    {
+        public ContentNestedData Deserialize(string data)
+        {
+            // by default JsonConvert will deserialize our numeric values as Int64
+            // which is bad, because they were Int32 in the database - take care
+
+            var settings = new JsonSerializerSettings
+            {
+                Converters = new List<JsonConverter> { new ForceInt32Converter() }
+            };
+
+            return JsonConvert.DeserializeObject<ContentNestedData>(data, settings);
+        }
+
+        public string Serialize(ContentNestedData nestedData)
+        {
+            return JsonConvert.SerializeObject(nestedData);
+        }
+    }
+}