Add support for "expand" parameter on GroupApi.GetGroup()

[RyAndrew]

Describe the feature request?

The groups API supports expand=stats to get the number of users and apps for a group.

This api call functions as expected:
GET /api/v1/groups/00ga1c6156kOI1Kch297?expand=stats

"_embedded": {
    "stats": {
        "usersCount": 10606,
        "appsCount": 2,
        "groupPushMappingsCount": 0,
        "hasAdminPrivilege": false,
        "_links": {
            "self": {
                "href": "https://mytenant.okta.com/api/v1/groups/00ga1c6156kOI1Kch297/stats"
            }
        }
    }
},

New or Affected Resource(s)

groupapi

Provide a documentation link

https://developer.okta.com/docs/api/openapi/okta-management/management/tag/Group/#tag/Group/operation/getGroup

Additional Information?

No response