Improve the tests

1. The three parameterised test cases have ids with spapes and commas: 'NOT DEFERRED, NOT WORKFLOW', 'DEFERRED, NOT WORKFLOW', 'DEFERRED, WORKFLOW' and this confuses pytest called with the -k flag. The spaces and commas can be, in principle, escaped but I could not find how (backslash does not work). After replacing the ids with strings with no commas and spaces (suggestion: 'INSTANT', 'DEFERRED', 'WORKFLOW', respectively), then pytest -k works.
2. All tests in test_resources.py are for the WORKFLOW case and are skipped for the other cases. There should be another fixture to just produce the tests only for the WORKFLOW case so that the others do not show as skipped.