Function: Delete all notifications for by type.

Function: Delete all notifications for a user.

Function: Check if a user has access to a specific notification.

Function: Add a notification for a specific user, from a specific component.

Function: Delete a specific notification by its ID.

Function: Get a specific notification by its ID.

Function: Get notifications for a specific user.

Function: Delete notifications for a user by type.

Function: Delete notifications for an item ID.