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/Vi/RootService/ApplicationDisplayService/IManagerDisplayService.cs

@@ -0,0 +1,61 @@
+using Ryujinx.Common.Logging;
+
+namespace Ryujinx.HLE.HOS.Services.Vi.RootService.ApplicationDisplayService
+{
+    class IManagerDisplayService : IpcService
+    {
+        private static IApplicationDisplayService _applicationDisplayService;
+
+        public IManagerDisplayService(IApplicationDisplayService applicationDisplayService)
+        {
+            _applicationDisplayService = applicationDisplayService;
+        }
+
+        [Command(2010)]
+        // CreateManagedLayer(u32, u64, nn::applet::AppletResourceUserId) -> u64
+        public ResultCode CreateManagedLayer(ServiceCtx context)
+        {
+            Logger.PrintStub(LogClass.ServiceVi);
+
+            context.ResponseData.Write(0L); //LayerId
+
+            return ResultCode.Success;
+        }
+
+        [Command(2011)]
+        // DestroyManagedLayer(u64)
+        public ResultCode DestroyManagedLayer(ServiceCtx context)
+        {
+            Logger.PrintStub(LogClass.ServiceVi);
+
+            return ResultCode.Success;
+        }
+
+        [Command(2012)] // 7.0.0+
+        // CreateStrayLayer(u32, u64) -> (u64, u64, buffer<bytes, 6>)
+        public ResultCode CreateStrayLayer(ServiceCtx context)
+        {
+            Logger.PrintStub(LogClass.ServiceVi);
+
+            return _applicationDisplayService.CreateStrayLayer(context);
+        }
+
+        [Command(6000)]
+        // AddToLayerStack(u32, u64)
+        public ResultCode AddToLayerStack(ServiceCtx context)
+        {
+            Logger.PrintStub(LogClass.ServiceVi);
+
+            return ResultCode.Success;
+        }
+
+        [Command(6002)]
+        // SetLayerVisibility(b8, u64)
+        public ResultCode SetLayerVisibility(ServiceCtx context)
+        {
+            Logger.PrintStub(LogClass.ServiceVi);
+
+            return ResultCode.Success;
+        }
+    }
+}