IGeneralService Implement GetClientId and IsAnyInternetRequestAccepted (#749)

* IGeneralService Implement GetClientId and IsAnyInternetRequestAccepted

- Add nifm:a and nifm:u with a max sessions as comment since sm don't take care of sessions for now.
- Implement IGeneralService GetClientId based on RE (close #623).
- Implement IGeneralService IsAnyInternetRequestAccepted based on RE (close #624).
- Add some informations in IGeneralService CreateRequest.
- Fix a comment in IAccountService.

* Fix requested changes

Ryujinx.HLE/HOS/Services/Nifm/GeneralServiceManager.cs

@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Ryujinx.HLE.HOS.Services.Nifm
+{
+    static class GeneralServiceManager
+    {
+        private static List<GeneralServiceDetail> _generalServices = new List<GeneralServiceDetail>();
+
+        public static int Count
+        {
+            get => _generalServices.Count;
+        }
+
+        public static void Add(GeneralServiceDetail generalServiceDetail)
+        {
+            _generalServices.Add(generalServiceDetail);
+        }
+
+        public static void Remove(int index)
+        {
+            _generalServices.RemoveAt(index);
+        }
+
+        public static GeneralServiceDetail Get(int clientId)
+        {
+            return _generalServices.First(item => item.ClientId == clientId);
+        }
+    }
+}