Tasks confidentiality - accept confidential field when updating work item through GraphQL
Related to #368035 (closed) (and comment #368035 (comment 1034245983))
Work item's update mutation should accept a "base" argument (not widget) which allows toggling confidentiality for the work item. Because Work Item's update service uses Issue's update service, it should be just matter of accepting this confidential
argument and passing it down to the service, similar to Issue's update mutation.
Exposing confidentiality field is tracked in #368573 (closed)