Add `simple` attribute to group details endpoint
Zendesk: https://gitlab.zendesk.com/agent/tickets/51953
The List Projects API endpoint has a simple
boolean attribute that will instruct the endpoint to only return each project's ID, URL, name, and path. A customer requests that we add this same attribute to the List a group's projects endpoint.
This seems like it will probably be fairly simple as we can re-use what's already there for the mentioned project endpoint.