Add native IAM group support

[castrapel]

Add IAM group support to ConsoleMe

1. IAM user advanced editor should provide the ability to view, add, remove, request addition, and request removal of IAM groups
2. (Version 2 - Not required for initial implementation) It should be possible to edit an IAM group directly, which should allow the addition, removal, request addition, and request removal of managed policies from the group, and the addition, removal, request addition, and request removal of IAM users from the IAM group
3. (Version 3 - Not required for initial implementation) Support IAM group manipulation through the self-service policy wizard