Change the way VIP determines whether vessel is working or idle for estimating bunker consumption.

Currently VIP appears to use the L/D Rate per cargo to decide whether vessel is working or idle when estimating alongside port consumption. Would like to propose that system should determine idle or working based on whether any cargo is being loaded or discharged during port call. When there are many (30+) cargoes being handled in a single port call having to maintain L/D Rates to get system to estimate working consumption is cumbersome. (INC-128281)