[Admin Tools] Enable admins to view and reactivate deleted users from the UI in Canvas

[KyraK]

CSV-imports are great for SIS-integrations and bulk updates. However, it happens that we just wish to update one user status, i.e. reactivating a user. This would be easily done if admins have access to a list over deleted users and select users for reactivating.

Why? Stickyness can cause SIS-integrations not to update certain information. Instead of overriding all UI-changes, we admins would like to be able to edit a user status manually in the UI. Manually updating the user is much faster than running a CSV-import for just this one user. It would also be useful to have an overview of "archived" users and their SIS ID's. 

Generally, I can imagine other situations where this would be a useful feature. Basically all information that can be imported with a CSV can also be created/edited in the UI - so why not enable the same for user status changes?