[EuiDataGrid] Enhance column header actions popover to be keyboard navigable with up/down arrow keys#6017

cee-chen merged 6 commits intoelastic:mainelastic/eui:mainfrom

cee-chen:datagrid/column-header-actions-arrow-keyscee-chen/eui:datagrid/column-header-actions-arrow-keysCopy head branch name to clipboard