Refactor the friend namespace (#721)

* 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

Ryujinx.HLE/HOS/Services/Friend/IDaemonSuspendSessionService.cs

@@ -7,14 +7,22 @@ namespace Ryujinx.HLE.HOS.Services.Friend
     {
         private Dictionary<int, ServiceProcessRequest> _commands;
 
+        private FriendServicePermissionLevel PermissionLevel;
+
         public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => _commands;
 
-        public IDaemonSuspendSessionService()
+        public IDaemonSuspendSessionService(FriendServicePermissionLevel permissionLevel)
         {
             _commands = new Dictionary<int, ServiceProcessRequest>
             {
-                // ...
+                //{ 0, Unknown0 }, // 4.0.0+
+                //{ 1, Unknown1 }, // 4.0.0+
+                //{ 2, Unknown2 }, // 4.0.0+
+                //{ 3, Unknown3 }, // 4.0.0+
+                //{ 4, Unknown4 }, // 4.0.0+
             };
+
+            PermissionLevel = permissionLevel;
         }
     }
 }