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

src/Radarr.Http/REST/RestModule.cs

@@ -1,11 +1,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.Json;
 using FluentValidation;
 using FluentValidation.Results;
 using Nancy;
 using Nancy.Responses.Negotiation;
-using Newtonsoft.Json;
 using NzbDrone.Core.Datastore;
 using Radarr.Http.Extensions;
 
@@ -248,7 +248,7 @@ namespace Radarr.Http.REST
             {
                 resource = Request.Body.FromJson<TResource>();
             }
-            catch (JsonReaderException e)
+            catch (JsonException e)
             {
                 throw new BadRequestException($"Invalid request body. {e.Message}");
             }

src/Radarr.Http/REST/RestResource.cs

@@ -1,10 +1,10 @@
-using Newtonsoft.Json;
+using System.Text.Json.Serialization;
 
 namespace Radarr.Http.REST
 {
     public abstract class RestResource
     {
-        [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
         public virtual int Id { get; set; }
 
         [JsonIgnore]