Converting retained shifts to ad-hoc shifts

In ASV a retained shift can now be converted to an ad-hoc shift. When a backfilled booked off shift is cancelled, the relief employee's shift enters an "Action Required" (AR) status. Then line managers must decide if the relief employee should still work the shift. If the decision is to continue to work this additional shift, the shift is "retained". As part of this retaining process, the shift is converted to an ad-hoc shift. This ad-hoc shift's activity is set to the activity from the shift label's original configuration.