What are the differences between toBroadcast and toArray methods

1. Purpose:
- `toBroadcast()`: This method is used to define the data that should be broadcast to the frontend when a notification is broadcasted.
- `toArray()`: This method is used to define the data that should be returned when the notification is converted to an array, for example, when the notification is stored in the database.

2. Return Type:
- `toBroadcast()`: This method should return a `Illuminate\Notifications\Messages\BroadcastMessage` instance, which contains the data to be broadcasted.
- `toArray()`: This method should return an array, which contains the data to be stored or returned as an array representation of the notification.

3. Broadcast vs. Non-Broadcast:
- `toBroadcast()`: This method is only used when the notification is being broadcasted using Laravel's event broadcasting services.
- `toArray()`: This method is used for all types of notifications, including non-broadcast notifications, such as mail, database, and SMS notifications.

4. Customization:
- `toBroadcast()`: You can customize the data that is broadcasted, such as adding additional fields or modifying the existing ones.
- `toArray()`: You can customize the data that is returned as an array representation of the notification, which can be useful for storing the notification in the database or returning it in an API response.

In summary, `toBroadcast()` is used specifically for defining the data that should be broadcasted when a notification is sent using Laravel's event broadcasting services, while `toArray()` is used for defining the data that should be returned as an array representation of the notification, which can be used for various purposes, such as storage or API responses.