REST API to bulk change or delete user aliases

CWD-1469 introduced a REST API to manage user aliases.

Because aliases refer to usernames, they become orphaned when a user is renamed or deleted (CWD-2179). The orphans are difficult to track and eliminate, and they stay behind occupying the alias name and preventing new users (or the renamed user) from re-using the alias.

The current REST API (CWD-1469) offers a solution: the aliases can be listed, removed and added individually. However, if the number of applications is high, that involves 1+2N calls.

As a REST client, I would like to have an API in Crowd to change or delete all the aliases (for all applications) for a username.