Merge etn main tests into etnservice

[PietrH]

Some tests are still using expect_is(), something that I fixed in etn, tests from etn main should be merged with this fork. However, some changes might be present in the API branch: v2.3 as well, so a difference with that might be useful as well.

[PietrH]

Then again, it might make sense for the tests to run on {etn} instead. As there they can run via CI, via the API...

For the paginated detections function: get_acoustic_detections_page() the original test from get_acoustic_detections()

Proposal:

• User facing arguments should be tested in etn, test the behaviour of the functions towards user expectations
• Functionality to do with how the functions are called is tested in etnservice, things to do with connections and pagination for example.