A recent change introduced a configuration option in the ./tests/test.yaml file (default location) which allows juju wait to be used rather than waiting on various workload messages. This, unfortunately, breaks mojo tests as they don't use a tests.yaml. This change refactors that code, and enables a 'use_juju_wait' to be passed into the relevant functions, and a new command line option (default true) to disable using juju wait.