Dedup astarpa2 and pa-base-algos #25
Description
pa-base-algos came first and contained some generic baseline implementations of band doubling and (Bi)WFA for both linear and affine costs.
Then astarpa2 copied a lot of the band doubling and blocks code, but modified it for bitpacking and removed the generics that allow for affine costs.
Ideally the two trees are merged or deduplicated a bit, but since one is specific for bitpacking and the other is generic, this is probably tricky.