Add metadata to users or groups in Identity service

Hello,

A nice feature that I wasn't able to find is to add metadata properties to users and groups (or have an extra couple of fields to fill by default). A nice example for us is to specify metadata regarding:

• User department (Engineering, Operations, QA...)
• User location (factory, region, country)
• Group description (if we create groups as role groups it's good to have a description of it).

With groups you can somehow build some elements of the above, but we'll end up creating lots of groups for a 1-2 people each. 

Thanks