add deprecated status for users

[sformel]

Would it be possible for a user to be given a deprecated status?

We have a growing list of users who have new email addresses (largely driven by the exodus from the US govt). We don't want to delete the old user profile, but we also want to ensure it's not a security concern, or used accidentally. Ideally, the deprecated status would lock the user out and would require the admin to change their status before they were allowed back in.