Track rendered work preview for each shipment

[StrictlySkyler]

Currently, if the values change, we're not tracking older settings.

Ideally we could view a history of all of the settings used for a particular harbor, and perhaps even a way to roll back to a specific point in time.

[StrictlySkyler]

This is tracked today, after a fashion, in that each Shipment also records the manifest used when it triggered, and this contains all the values assigned to the Harbor at the time of the Shipment.

Really, this seems like it's worth changing the "Work Preview" figure for a historical shipment to be "Work Performed", showing the values of the manifest at that time. There's a question of whether or not it's worth showing the "current" settings for the harbor in that figure as well, but perhaps merely providing a link or reminder to the current Ship Lane page is sufficient. A user could, for example, open a new Ship Lane tab and compare with the historical one.