Add the ability to get parentGroupId from the Group model

• Type: Bug
• Status: Closed
• Resolution: Won't Fix
• Affects Version/s: 5.1.2, 5.2.3, 6.0.1 RC
• Fix Version/s: 6.0.4 GA
• Component/s: ~ [Archived] Sites Management
• Labels: None
• Branch Version/s:
  5.2.x

Modify the group interface and the GroupImpl to add a getParentGroupId() function