Removing link duplicates

[Martin-Rey]

Hi,

This a clean attempt at addressing the comments in #182, after rebasing against the main branch following #183 proved unnecessarily messy.

I think the tests cover all cases described in #182. The only remaining question is whether we should attempt to delete non-maximal duplicate links, and if yes, whether the behaviour should be to keep the most recent addition to the database, or the highest weight.

[apontzen]

pre-commit.ci autofix

[apontzen]

Thanks - just to understand, this current version will keep multiple links between the same two halos, with the same name, but different weights, is that correct?

This is an edge case that probably nobody will ever see, but still I think that's probably not what most people would expect. I think there is a good argument for dropping all links with the same name linking the same two halos. I am happy with this being done on the basis of keeping the most recent addition rather than the highest weight.

[Martin-Rey]

The latest change should now remove links with the same name, between the same halos, but with different weight. I added a test to verify that the latest link addition to the database is retained.

The maximal duplicate (same halos, same weight, same name) might feel like an edge case, but it actually occurs naturally when re-importing properties multiple times in an existing database (the current importer duplicates properties and links without checking if they already exist #162). And this was my base use case for developing this feature :)

Let me know if you have any last comments/suggestions