feat: Add method to convert global ids to local ids for PlacementSet

[filimarc]

Since the need to deal with global ids for targetting classes i add a method to convert ids called: convert_to_local.

it is linked to the PR in bsb-core: dbbs-lab/bsb-core#898

• Add test

[Helveg]

Can you add some tests so that I can debug how your algorithm works? It still looks way too complicated with way too many array lookups like np.isin etc for what it should be doing. In my mind it should:

For every element in ids, find the chunk it belongs to, use the chunk offset + cell-in-chunk offset to get the local id.

That should not take 10+ array operations to achieve, so I'd like to double check what's going on in your array operations :)

[filimarc]

I try to refactor to follow your logic, still i haven't found a way to filter ids for local chunks, to prevent to convert ids not related to that chunk and also to compute the local chunks offset, without using lookups. Anyway i am using isin only for chunk id lists, so should be an order of thousands of elements, i think it should be fast.
But maybe you have a better solution for that, if you think it could help i will add some tests.

[drodarie]

@Helveg, Filippo implemented your feedback. Could you please review this PR, we would like to bump the main bsb package.