[#372] Review onTurnError use cases - Add sample

[ceciliaavila]

Fixes #372

Description

This PR adds a sample to showcase how to configure a custom error handler in the AgentApplication to replace the default onTurnError function from the adapter.

Detailed Changes

• Created a new sample under samples/basic named errorHandling.ts.

Testing

These images show the sample working:

• Here the custom error handler is executed, logging the error to the console and sending a message to the user.

• Here the default onTurnError is executed with the DEBUG=* setting in the .env file. A trace activity is sent, and the detailed error is logged.