Refactor worker/entity tests

[ktuite]

Addressed in PR #1021

There are a number of tests in tests/integration/worker/entity.js that were made before we had more of the API in place that we might be able to remove. This file could be made to focus just on the entity worker?

I find myself either forgetting about this file, or over-relying on this file as a kind of catch-all of entity workflow test scenarios. For example, I'm writing entity update tests here because I'm not sure where else they should go... in the GET entities/uuid endpoint? Sometimes I want to test one scenario, like entity updates, and maybe check that multiple endpoints look as expected instead of duplicating the scenario across the tests for different endpoints.

Do other people have issues with not knowing where to put tests? Suggestions?

[matthew-white]

For getodk/central#385, existing tests of the form worker were in test/integration/api/forms/forms.js and test/integration/api/forms/draft.js. I think that's because the worker is triggered by the endpoints to create a form or draft or to publish a draft. By that logic though, we should test the entity worker in the tests of the submission creation endpoints, and that doesn't feel right. 🤔 I feel like there are multiple reasonable options here. If this feels like a special case since it touches so many endpoints and is about a larger workflow, one option might be that we move these tests to their own file or set of files.