Request / Require Reboot following Full backup Restore

[wittelw]

As noted in Add ons not working properly after snapshot restore, add-ons will not function correctly after restoring a Full backup to a new installation until a Reboot is done.

Ideally, once the backup has been restored, the user should see a Reboot dialog (or at least request / notification) at first login. This requirement should not be left to the user to discover via forums. It would also be helpful to add this detail to https://www.home-assistant.io/common-tasks/os/#restoring-a-backup