Add all matching line items to consolidate into 1 line item for invoicing

Similar to the space bookings where you can choose to consolidate to 1 line in the invoice, this feature would put all charges we add to someone's bill to consolidate to 1 line - we dont mind if the variables are added 5 days apart, we would like the quantity and price of the 1 line item to update rather than have 1 line item per charge.