New: Use System.Text.Json for Nancy and SignalR

src/Readarr.Http/Extensions/NancyJsonSerializer.cs

@@ -1,5 +1,6 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
+using System.Text.Json;
 using Nancy;
 using Nancy.Responses.Negotiation;
 using NzbDrone.Common.Serializer;
@@ -8,6 +9,13 @@ namespace Readarr.Http.Extensions
 {
     public class NancyJsonSerializer : ISerializer
     {
+        protected readonly JsonSerializerOptions _serializerSettings;
+
+        public NancyJsonSerializer()
+        {
+            _serializerSettings = STJson.GetSerializerSettings();
+        }
+
         public bool CanSerialize(MediaRange contentType)
         {
             return contentType == "application/json";
@@ -15,7 +23,7 @@ namespace Readarr.Http.Extensions
 
         public void Serialize<TModel>(MediaRange contentType, TModel model, Stream outputStream)
         {
-            Json.Serialize(model, outputStream);
+            STJson.Serialize(model, outputStream, _serializerSettings);
         }
 
         public IEnumerable<string> Extensions { get; private set; }

src/Readarr.Http/Extensions/ReqResExtensions.cs

@@ -27,10 +27,8 @@ namespace Readarr.Http.Extensions
 
         public static object FromJson(this Stream body, Type type)
         {
-            var reader = new StreamReader(body, true);
             body.Position = 0;
-            var value = reader.ReadToEnd();
-            return Json.Deserialize(value, type);
+            return STJson.Deserialize(body, type);
         }
 
         public static JsonResponse<TModel> AsResponse<TModel>(this TModel model, NancyContext context, HttpStatusCode statusCode = HttpStatusCode.OK)