fix(grid-column-groups, pivot): render a hidden row with headers for accessibility purposes - 20.0.x#16019

kacheshmarova merged 3 commits into20.0.xIgniteUI/igniteui-angular:20.0.xfrom

bpachilova/column-groups-a11y-16017IgniteUI/igniteui-angular:bpachilova/column-groups-a11y-16017Copy head branch name to clipboard