[E2E][JF] Implement JF Administrator and Datastore Servers - Phase 2

[doru91]

Please check comment: #38842 (comment). As described in the comment, #38842 implements work around 3 attributes only:

• mNodeInformationEntries
• mGroupKeySetList
• mAdminEntries

If I look in the spec in section 11.24.6. Attributes I see there are 13 attributes.

Same discussion for the commands of the Joint Fabric Datastore (#38842 implements only a very restricted set of commands: AddPendingNode, UpdateNode, RemoveNode).