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/IWindowController.cs

@@ -1,29 +0,0 @@
-using Ryujinx.Common.Logging;
-
-namespace Ryujinx.HLE.HOS.Services.Am
-{
-    class IWindowController : IpcService
-    {
-        public IWindowController() { }
-
-        [Command(1)]
-        // GetAppletResourceUserId() -> nn::applet::AppletResourceUserId
-        public ResultCode GetAppletResourceUserId(ServiceCtx context)
-        {
-            Logger.PrintStub(LogClass.ServiceAm);
-
-            context.ResponseData.Write(0L);
-
-            return ResultCode.Success;
-        }
-
-        [Command(10)]
-        // AcquireForegroundRights()
-        public ResultCode AcquireForegroundRights(ServiceCtx context)
-        {
-            Logger.PrintStub(LogClass.ServiceAm);
-
-            return ResultCode.Success;
-        }
-    }
-}