[1.1.100] Train pumps do not respect fluid system restrictions

[Hexicube]

I know that there's been a general surrender when it comes to ensuring fluid systems are strictly one-fluid, but in the case of train unloading it's particularly easy for this to happen to the point where I think a new player could come across this. Having to use circuits to solve this problem or being forced to make multiple unloading stations, despite the fact for items you can filter inserters (pumps have no filter option unless you use circuits), seems unreasonable to me.

There should either be a filtering option on train unloading pumps, or a check specifically for the case of train unloading pumps.

Example: https://i.imgur.com/ZWS5iEo.png

[SupplyDepoo]

It would be a shame if fluid sushi is impacted negatively (sending different fluids down the same pipe at different times), so if the pump logic is changed, it would be better if it is enabled whenever there's a matching fluid downstream, instead of disabling it whenever there's a different fluid. Both cases would fix Hexicube's scenario, but the first one would not affect fluid sushi.

[Loewchen]

Don't make feature requests in Bug reports.