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/Am/AppletAE/IStorage.cs

@@ -0,0 +1,21 @@
+namespace Ryujinx.HLE.HOS.Services.Am.AppletAE
+{
+    class IStorage : IpcService
+    {
+        public byte[] Data { get; private set; }
+
+        public IStorage(byte[] data)
+        {
+            Data = data;
+        }
+
+        [Command(0)]
+        // Open() -> object<nn::am::service::IStorageAccessor>
+        public ResultCode Open(ServiceCtx context)
+        {
+            MakeObject(context, new IStorageAccessor(this));
+
+            return ResultCode.Success;
+        }
+    }
+}