[FEATURE]: Column grouping

[truejay]

Is your feature request related to a problem? Please describe

Can not group columns. Vanilla Datatable does have column grouping (complex headers): https://datatables.net/examples/basic_init/complex_header.html

Describe the solution you'd like

Be able to group columns as well as styling for the group/cell/row.

Describe alternatives you've considered

There are no alternative when using react-data-table-component. Other libraries like ag-grid, mui features column grouping. Only react-data-table-component is missing the feature.

Additional context

None.