Kingsmarch mappers - gold drain estimate for all queued maps

Currently the estimate of when the "work will be done" or when the treasury runs out of gold only counts currently run map.

It makes sense that if mapper dies, the progress will be paused and the total time can vary.

It would be useful to have estimate of how long it would take to run all the maps in the queue (assuming no mapper dies), so we can know if we have enough gold stored, or in how long it will run out assuming the mappers will continue running the maps. Regardless if it will be eventually met or not.

+1. Been an annoying issue since settlers release