friends: Implementation of IServiceCreator (#704)

- Add INotificationService (close #621)
- Add IDaemonSuspendSessionService

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

@@ -0,0 +1,20 @@
+using Ryujinx.HLE.HOS.Ipc;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS.Services.Friend
+{
+    class IDaemonSuspendSessionService : IpcService
+    {
+        private Dictionary<int, ServiceProcessRequest> _commands;
+
+        public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => _commands;
+
+        public IDaemonSuspendSessionService()
+        {
+            _commands = new Dictionary<int, ServiceProcessRequest>
+            {
+                //...
+            };
+        }
+    }
+}