integrationtests + collectiontests: also compare input feature ids

[jdries]

We often have integrationtests failing due to small differences in input products.
Write a generic approach to also compare derived-from links in addition to comparing the output.
Ideally, the test report contains both results, so not having one failure blocking the result of the other comparison, they are both relevant to get a view on the issue.

Same applies to CollectionTests.