azure role assignment delete will delete all assignments when --assignee is empty string

[yungezz]

az feedback auto-generates most of the information requested below, as of CLI version 2.0.62

Describe the bug

Fork the issue from #13577, to track specific issue from customer when --assignee is empty string, az role assignment delete will delete all assignments. After fix, az will throw error when --assignee is empty string

I accidentally did this:

az role assignment create --assignee "$SOME_VAR" --role "Owner"

SOME_VAR was accidentally set to empty string. I did not get any prompt and EVERY OWNER WAS DELETED.I lost access to my subscription. Cannot even file a support ticket cause I lost permissions.
Is there a way to fix this?

To Reproduce

Expected behavior

Environment summary

Additional context

[yungezz]

let's fix the specific issue firstly.