Add property to MvcNewtonsoftJsonOptions to support culture-aware deserialization

[martincostello]

Background and Motivation

Adds a new option to the Newtonsoft.Json-based NuGet package for MVC to enable culture-aware deserialization of request bodies as proposed by #9994 (comment).

I missed the need to propose the API before doing the PR as I was looking at help wanted issues, so the below is already implemented in #31331.

Proposed API

namespace Microsoft.AspNetCore.Mvc
{
    public static class MvcNewtonsoftJsonOptions
    {
+       public bool ReadJsonWithRequestCulture { get; set; }
    }
}

Usage Examples

The application would opt-in to the behavior like so:

services.AddControllersWithViews()
        .AddNewtonsoftJson(options => options.ReadJsonWithRequestCulture = true);

Which would then allow requests such as the following to succeed:

curl http://localhost:20991/api/values/date3 -X POST -d "{\"Date\":\"15\/5\/2019\"}" -H "culture: es-MX" -H "Content-Type: application/json"

Alternative Designs

None considered.

Risks

None known - new behaviour this flag would enable would be guarded behind it, with its default value being false to retain current behaviour.

[davidfowl]

I feel like ReadJsonWithRequestCulture is redundant? What about UseCurrentCulture ? There's no such thing as request culture.

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.