translateDataSourceResultGroups bug with null group

[jarnaiz]

Description

Reported here: https://www.telerik.com/forums/progress-kendo-data-query-with-group-and-null-value
and here again: #954 (comment)

There are a bug when using translateDataSourceResultGroups when process a group with null value.

The first group with field 'estadoDenominacion' value 'null' is not rendering.

Plan

KendoReact

Steps To Reproduce

Look at the example: https://stackblitz.com/edit/react-hmnv9d-df9tuauq?file=package.json,app%2Fmain.jsx,app%2Fproducts-loader.jsx

The responseJSON var in the product-loader.jsx is a is a response of our .NET Core API, our backend is something like this:

using Kendo.Mvc;
using Kendo.Mvc.Extensions;
using Kendo.Mvc.UI;

public DataSourceResult Get([DataSourceRequest] DataSourceRequest requestl) 
{
    return Repository.Get().ToDataSourceResult(request);
}

Screenshots or video

No response

Actual Behavior

The translateDataSourceResultGroups process the groups and set as value of the group undefined when the value of the group was null then the grid component doesnt render the group when i want to see the null or a empty group

Expected Behavior

Check at this with a workaround applied: https://stackblitz.com/edit/react-hmnv9d-ztissicb

Browser

Chrome, All

Browser version

latest

OS type

MacOS, Windows

OS version

No response

Last working version of the KendoReact package (if regression).

No response