[PATCH] Batch-trained traders fail to arrive at market rally point

[zoot]

Steps to reproduce:

1. Build two markets, market A and market B.
2. Draw a zig-zagging line of several rally points from market A to market B.
3. Train a batch of traders in market A.

What happens:

The batch of traders follow the rally points, but halt at the second-to-last point (the one just before the destination market).

What should happen:

The traders should arrive at market B and continue walking back and forth between the markets.

[zoot]

Batch of trader stopped at second-to-last rally point.

[leper]

WIP fix for #1822 and #1821

[leper]

The patch works and fixes the issue, but the code is sort of ugly so I will not commit this patch as it is now. One of the problems is that SetupTradeRoute depends on the entity to have the Trader component, which for the formation controller isn't true.

Moving the logic from SetupTradeRoute to Order.Trade could work, but would make queued trading (move first, then start to trade) a bit strange.

I suppose fixing this would have some code overlap with the first point of #1207.

[mimo]

In 14697:

allow the possibility to define route with waypoints when doing trade, fixes #1207, #1821 and #1822