Provide an option to drag a cell content and drop it to another cell for both default and skia render modes

Makes this feature also available for skia cell renderer

Provide an option to set explicit style to the grouping panel, for example expose GroupingPanelStyle property. 

Currently, the option is using an implicit style targeting the DataGridGroupingPanel

<Style TargetType="telerik:DataGridGroupingPanel">
    <Setter Property="BackgroundColor" Value="Red"/>
    <Setter Property="HeaderText" Value="Hello to group"/>
    <Setter Property="CornerRadius" Value="10"/>
    <Setter Property="BorderThickness" Value="2"/>
    <Setter Property="BorderColor" Value="Blue"/>
</Style>

when changing property value programmatically, the row background style selector does not apply. You need to scroll the data or resize the control, then the change applies.

The selector works when editing the datagrid value trough the UI, but does not work when changing the value programmatically.

I want to select multiple rows by selecting one and then holding down the shift key and selecting more.

For example in WPF DataGrid there is an Extended multiple selection option: https://docs.telerik.com/devtools/wpf/controls/radgridview/selection/multiple-selection 

For the distinct values, there is a bool property that allows you to hide the distinct values: ShowDistinctValuesFilter. 

Expose similar way for the Show Rows with Values options

When using ImageButton inside a CellTemplate, the image does not display initially. When you resize the window image is displayed. 

Workaround:

Use Image instead of ImageButton