Fix persistence issue in test_app_id_special_chars

[mastastny]

Split shared service into two (headers and query) so credentials_location is not mutated between parametrized tests. Fixes 403 on persistence load when headers test runs after query test overwrote the setting.

reproducer:
pipenv run python -m pytest -m 'not flaky' --fuzz --drop-nopersistence --store x testsuite/tests/fuzz/test_app_id_special_chars.py
pipenv run python -m pytest -m 'not flaky' --fuzz --drop-nopersistence --load x testsuite/tests/fuzz/test_app_id_special_chars.py

[mdujava]

can't we put service_1 if _ else service_2 into the @pytest.parametrize?

[mastastny]

can't we put service_1 if _ else service_2 into the @pytest.parametrize?

I don't think so. Parametrize values are resolved at collection time, before fixtures are instantiated, so we can't reference fixture objects there. But I might be missing something, do you have a specific approach in mind?

[mdujava]

if there is "headers" why not put here header_service fixture directly (query_fixture instead of "query"), similar how we in some tests use either prod_client or api_client.

[mastastny]

Good point, but credentials_location is also used in the assertion (line 236) to decide whether to check headers or params, so we'd still need it as a value, not just a fixture reference.