* refactoring result codes
- Add a main enum who can handle some orphalin result codes and the default `ResultCode.Success` one.
- Add sub-enum by services when it's needed.
- Remove some empty line.
- Recast all service calls to ResultCode.
- Remove some unneeded static declaration.
- Delete unused `NvHelper` class.
* NvResult is back
* Fix
* Refactor the friend namespace and UInt128
This commit also:
- Fix GetFriendsList arguments ordering.
- Add GetFriendListIds.
- Expose the permission level of the port instance.
- InvalidUUID => InvalidArgument
* friend: add all cmds as commments
* add Friend structure layout
* Rename FriendErr to FriendError
* Accurately implement INotificationService
* Fix singleton lock of NotificationEventHandler
* Address comments
* Add comments for IDaemonSuspendSessionService cmds
* Explicitly define the Charset when needed
Also make "Nickname" a string
* Address gdk's comments
