Refactoring HOS folder structure (#771)

* Refactoring HOS folder structure

Refactoring HOS folder structure:

- Added some subfolders when needed (Following structure decided in private).
- Added some `Types` folders when needed.
- Little cleanup here and there.
- Add services placeholders for every HOS services (close #766 and #753).

* Remove Types namespaces

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

@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Ryujinx.HLE.HOS.Services.Nifm.StaticService.GeneralService
+{
+    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);
+        }
+    }
+}