Introduce 'verbose' parameter for controlling printed output

[stmartin]

Describe the new feature or enhancement

The printed output can be quite lengthy when running simulations (e.g., simulate_steady_state). It would be nice to be able to control the level of information printed.

Please provide a clear and concise description of what you want to add or change.
Introduce an optional verbose parameter (default=True) that allows to control the printed output.

Please describe how you would use this new feature.
result = scenario.simulate_steady_state(verbose=False)
or
results = scenario.simulate_pulse(verbose=False)

Describe your proposed implementation

def simulate_steady_state(self, [...], verbose: bool=True)