[Automation] Add support for workplace staffing signals #128
Description
Each workplace building tracks numeric (int) values for Workplace.DesiredWorkers, Workplace.MaxWorkers, Workplace.NumberOfAssignedWorkers, as well as booleans for Workplace.Understaffed and Workplace.Overstaffed.
Currently, these can be used in automation scripts via the access operators (getnum Workplace.<variable>). Exposing these as building signals for workplaces would allow for new automations like pausing/unpausing breeding pods and/or bot assemblers when a building is fully staffed or understaffed.