Swap range limitation and node sampling for local btw calc

[mszell]

Gaps don't work because 300 sampled nodes are range-restricted, leading to way too few nodes sampled. So range-restriction and sampling should be swapped and tried out first. Double-check output for Copenhagen with https://fixbike.net/ - should be very similar.

If it doesn't work well, needs to be re-implemented with the original igraph method as it probably should have been done in the first place due to btwness complexity.

[mszell]

As just discussed with @Manuel-Knepper, one major issue seems to be a wrong definition of protected bike infra, which leads to weird gaps:

This should be fixed first, by rewriting the protected bike infra definition exactly as in growbikenet. Then we will see if it works, or if there are still issues left.