Support $count for group members and owners
Currently $count is not supported on `directoryObjects` like users and groups. Although it would be great to know how much members / owners are in a group. The only way right now is via querying the members or owners endpoint of the group and checking the array length. Depending on the number of members, this could lead to multiple calls.
It would be great that the `$count` parameter would be supported so that only one call is required.
This work has started for both group members and owners. ^JT