Prepare a payroll for update

This endpoint will build the payroll and get it ready for making updates. This includes adding/removing eligible employees from the Payroll and updating the check_date, payroll_deadline, and payroll_status_meta dates & times.

Notes:

• Will null out calculated_at & totals if a payroll has already been calculated.
• Will return the version param used for updating the payroll

scope: payrolls:write