#5557 Need to show confirmation when user deleting leave type/s

[nilanga Nayanajith]

Version : OrangeHRM 2.6.6

Description : There should be a warning message when user deleting a defined leave type.

Steps :

1.Define leave type as casual
2.Now select that leave type and click on delete.System delete the leave type without showing any confirmation message

Fix : Need to show proper confirmation message and it should be expressed "Undelete option" also.