e2e sample interaction start page

[olpa]

There is a sample interaction on the start page. This code should be used in the integration tests.

[olpa]

New concept: Rework the test https://github.com/olpa/ailets/tree/master/example-trace-messages to a command-line tool. Parameters:

• one step
• stop at
• dry run
• print state
• load state
• prompt on the command line or from stdin