[Accessibility] Allow setting of the aria-label of table row selection checkboxes

[peteharverson]

Currently there is no way to override the default aria-label for table row selection checkboxes. It is hardcoded as Select this row. For screen reader users we need to provide extra information to identify the row that is being checked/unchecked e.g. 'Select ML job apache logs'.

See https://github.com/elastic/eui/blob/master/src/components/basic_table/basic_table.js#L770-L785

Originally filed as issue elastic/kibana#28390