[Suggestion] Switch Niobium and Multipurpose Pipes

[BlueTemplar]

Currently, the more advanced Multipurpose pipes are functionally better in every way than the Niobium pipes. (And are also cheaper !)

Sadly, they :
- don't look nearly as great,
- are awkward in terms of figuring out which direction they are pointing, and to distinguish underground and regular pipes,
- and also don't "fit" graphically with most pY buildings (while Niobium pipes do).

So I suggest just switching them in terms of tech tree placement and max underground length, so that the shiny Niobium pipes reclaim their rightful place at the top of the pipe order !

(And the release of Alternative Energy seems to be the best moment to do it, since it sounds like our Alien Life bases are screwed *anyway* ?)

The only tricky part that I see are the costs :
We probably don't want the tier 2 (before Niobium, now Multipurpose) pipes to be made *only* from niobium,
but having them only use rubber (+ plastic ? / + copper ??) (that they already use as Multipurpose pipes), without any niobium, seems to be more viable (and rename them to Rubber pipes ?),
also the "cost" of rubber (mostly in terms of titanium) varies quite wildly across the game.
(While the tier 3 (before Multipurpose, now Niobium) pipes could totally still *just* need the expensive & rare niobium to make them. Or throw in some extra requirement, like stainless steel (bolts?).)

Also, the cost of the 3 pipe tiers is *all over the place* when considering the Advanced Casting recipes.
And multipurpose pipes suddenly need copper, and only copper (+plastic for plain ones) to make ??
(I should probably add some Helmod pics...)

P.S.: Don't forget about aspects like HP and resistances : to vehicle impact (multipurpose pipes seem to be completely immune !), acid, fire...

[pyanodon]

multipipes got a rework to make it looks better in the intersections