Review tests

[jdeschamps]

Tests have gone a bit out of hand. We split the CI into three different types to accommodate the very lengthy LVAE tests, and to minimize the uploads to CodeCov.

We should review all tests to make them lighter, and offload the heavy testing to another platform (e.g. GitLab).

In addition:

• generalize np.testing.assert_array_equal
• review skipped tests

[melisande-c]

Maybe we want to split the tests so we have API tests separately to unit tests. Once we're at v1.0.0 we probably don't want to break the API between versions, so we could have tests that just look at function inputs/outputs and warn us if anything changes int a PR.

[jdeschamps]

That's a good point. Given that we expect CAREamics to be consumed by third-party software, that would indeed make sense to make a specific CI for API and integration related tests, that would only run on linux for instance. That way we would consume less resource.