Action Message Callback

• Purpose:
  Handles incoming action messages, such as credential approval notifications.
• Functionality:
  Logs the model details and returns an object indicating that the action should be deferred (i.e., handled later).
• Usage:
  Triggered when the agent receives an action message from the backend, allowing the application to decide when to process the message.
• Example:

 actionMessageCallback: async (model) => {
    console.debug(`Accept credential approved:\n${JSON.stringify(model, null, 2)}`);
    return { action: ActionMessageCallbackAction.Later };
  },

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