[Feature Request] Allow output files

[miri-bar]

From what I could find, results can only be saved to an SQL DB.
I don't use a DB when I run the CLI, and so at the moment, my only option to view the results is from stdout.
It would be helpful if there will be an option to save the results as files in CSV or JSON formats.
As a first phase - at least the final results (the optimal values of the parameters to tune).
As a second phase - have the final results + results from each trial.