samba-tool contact management

• samba-tool user/group/computer/... edit: Avoid base64 encoded strings in editable ldif if possible. Use clear text arguments strings if possible.
• samba-tool: implement contact management commands Available subcommands:
  • create - Create a new contact.
  • delete - Delete a contact.
  • edit - Modify a contact.
  • list - List all contacts.
  • move - Move a contact object to an organizational unit or container.
  • show - Display a contact.