Views sort criteria and click-sort table headers do not work together as expected

This patch modifies \Drupal\views\Plugin\views\style\Table::buildSortPost() to add existing sort filters after the click-sort has been processed.

This will ensure that either value of Override normal sorting if click sorting is used will keep existing sort filters, but the checking will ensure the click-sort is sorted first, while un-checking will ensure the click-sort is sorted last.

IS should be updated to include proposed solution

As a bug will need a test case showing the problem.

Thanks.