Lasers can now go through transit tubes

Fixes #5827
They'll still block ballistic projectiles, and I think that's reasonable, as they are reinforced tubes for vacuum transportation and thus can stand a few shots.
As for blocking movement, I'm ambivalent on this. I feel like it wouldn't make sense if tubes were climbable (I mean, they can fit a lot of people inside), but using them as barricades is pretty shit too. Opinions?