Default --wait for the option submit-command for run-ensemble

When using the option `--submit-command` for run-ensemble, the jobs for the model are submitted but the usual logger information like 'model finished!' is missing and executing all the probtest commands consecutively becomes quite bothersome as e.g., the stats are generated before the runs are finished.
This only happens if `--wait` is not added to the command, maybe it would make sense to add `--wait` as a default submit command.

Start at the run-ensemble CLI handling for --submit-command and --wait. Reproduce a submission without --wait, then confirm that making --wait the default preserves the usual completion logger and prevents statistics generation before the model runs finish.

Written by the indexing model from the issue text.