Refactor dialog

[secretsauceai]

There are a lot of print statements (and f-string print statements) in the CLI. It has been suggested to pull them out and let them be handled as a dialog JSON file. And it's always fun to handle dialog with slotting (ie NLG).

• Write a class to handle dialog
• Move dialog from the flows into a JSON file
• Test

[secretsauceai]

The dialog from get_base_model_flow.py has been moved into dialog.json as an example, however the other flows still have all of their print statements hard coded into the python files. To make it easier to change dialog and to have an overview of the steps, the dialog from all flows should be moved into dialog.json.