Implement groupingParams and onCreateGroupings

[mstijak]

This should work similar to how filterParams and onCreateFilter work on the grid.

[mstijak]

The feature is implemented and works like this:

<Grid     
     groupingParams:bind="$page.grouping"
     onCreateGrouping={(groupingParams) => [
         {key: {}, showFooter: true},
         ...(groupingParams || []).map(x => x.id)
     ]}

Is there a better name for the function from onCreateGrouping?

[nikolatechie]

onCreateGrouping has been renamed to onGetGrouping. Here's an example: https://docs.cxjs.io/examples/grid/dynamic-grouping