Migrate friends service to new IPC (#6174)

* Migrate friends service to new IPC

* Add a note that the pointer buffer size and domain counts are wrong

* Wrong length

* Format whitespace

* PR feedback

* Fill in structs from PR feedback

* Missed that one

* Somehow forgot to save that one

* Fill in enums from PR review

* Language enum, NotificationTime

* Format whitespace

* Fix the warning

src/Ryujinx.Horizon/Friends/FriendsPortIndex.cs

@@ -0,0 +1,11 @@
+namespace Ryujinx.Horizon.Friends
+{
+    enum FriendsPortIndex
+    {
+        Admin,
+        User,
+        Viewer,
+        Manager,
+        System,
+    }
+}