This diff introduces adding of `IsOnline` field to the DynamoDB database in the `DeviceSessionItem` entity.
To send notifications if the device is offline we need to distinguish the device state. To do this we will ping the device and change the device status (online/offline) in this database in this field.
More context is available in the Linear task description.
Related Linear task: [[ https://linear.app/comm/issue/ENG-1766/make-sure-the-device-is-offline-to-send-a-notification-to-wake-it-up | ENG-1766 ]]