find-users command

Please provide details on the following items. Failure to do so may result in deletion of your feature request.

What's the user value of this feature request?
To be able to find if users exist in their foundry

Who is the functionality for?
This functionality is for operators of foundries

How often will this functionality be used by the user?
How often will they use this feature?

Who else is affected by the change?
This would not be a breaking change as it would represent an addition to the core CLI

Is your feature request related to a problem? Please describe.
In our organisation we receive staff member leavers tickets for all members of staff who may or may not have accounts within our foundries, This is a standard procedure to ensure that all accounts across a wide range of business systems and functions are closed in a timely manner when a member of staff is due to leave. Currently we have to use the UAA client to check if the staff member has an account and then handle the ticket appropriately.

Describe the solution you'd like
a command to sit within the user command context that would enable checking if a user had an account or not

Describe alternatives you've considered
Our current work around is to log in to UAA using the UAA client and to perform checks directly on UAA. This is a slightly clunky process and would benefit from being part of the core CLI.