Investigate random test failures in jobcontroller's test_queue_consumer.py (and possibly others?)

[esmith1729]

Description of the issue

There are random test failures in pytest-jobcreator workflow, depending on what order the tests are run in. Known tests are:

• test_message_handler_on_json_decode_error - AssertionError: Expected 'error' to be called once. Called 0 times.
• test_message_handler - TypeError: test_start_consumer_will_handle_exceptions_as_warnings..raise_exception() takes 0 positional arguments but 1 was given
• There may be others

This may be due to test clean up not occurring properly, or something like that. investigate and try to fix these.