Commands can now delete model owner during context execution

SM commands can now delete a model during context execution withought crashing the SM.
Be mindful though as if your commands deletes the owner model of the attribute then the Context execution will be halted there. So if you create such a command make sure it's last in the queue if you're interested in having the other ones executed

Example

Terminating an account, and permanently deleting an entry. You probably want to first send an email. This means your emailing command should precede the deletion command.