Allow pumps to connect to slightly-slanted fluid wagons

[Epp]

Let me clarify: I understand that pumps will sometimes not connect to straight fluid wagons if any part of the train is on a curve and that this can be controlled with fluid_wagon_connector_alignment_tolerance. This is different. I want pumps to be able to connect to fluid wagons that are themselves partially sitting on curved rails, provided the curve is not too extreme. First, the intuitive argument:

It's just odd that the left works but NOTHING on the right does - the slant is very minor, even when exaggerated by zooming in like this.

05-27-2025, 10-20-24.png (958.84 KiB) Viewed 73 times

Second, the appeal to elegance: Since the minimum rail curve radius was increased in 2.0, you can no longer build a 1-2 fluid wagon on the biggest loop possible between two roboports, which leads to this atrocity:

05-27-2025, 10-29-26.png (878.85 KiB) Viewed 73 times

Look at how they massacred my boy!

I know the pump is complex with a big animation and static behavior. Reworking it to procedurally connect to ports within a given distance would be so darn cool, smooth, and would eliminate an entire class of train confusion and complaints, including mine.