Add IMvcCoreBuilder.AddJsonOptions extension method

[rynowak]

We don't have this defined for IMvcCoreBuilder only IMvcBuilder. This would be great to have even though you can setup options as part of AddJsonFormatters. Most of our examples refer to AddJsonOptions.

https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNetCore.Mvc.Formatters.Json/DependencyInjection/MvcJsonMvcBuilderExtensions.cs#L19

[javiercn]

My two cents #4965 (comment). This would be a good up for grabs

[Eilon]

Agreed.

[iscifoni]

I can do it ?

[Eilon]

@iscifoni I don't know, can you? 😄 If you want to give it a try, please let us know if you're working on it and we'll expect a PR from you!

[iscifoni]

Yes I can do it !! 😄

I start to do it today