Allow removal of user from all sites in org as an argument on `org:people:remove`

[gravelpot]

User story

As a workspace administrator, I want to be able to add a flag to the terminus org:people:remove command that will remove the specified user from all sites in the workspace as well as the workspace itself, so that I can de-authorize a user for both the workspace and sites with one action.

Additional information

This request is to supplement the existing terminus functionality for deleting users with the option to remove a workspace member from "Everything" that was added to the admin UI a while back: