[SAMBA 4 directory] Refactoring and clean up of directory structure

[SAMBA 4 directory] Refactoring and clean up of directory structure

- Adds more system objects which make sense to have them in SAMBA 4 also to
  have them when we add more and more services related to the directory (volume
  support, DFS, replication service, COM...)
- Make sure that "isCriticalSystemObject" and "showInAdvancedViewOnly" attributes
  are set correctly on each object