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/Sockets/Nsd/ResultCode.cs

@@ -0,0 +1,19 @@
+namespace Ryujinx.HLE.HOS.Services.Sockets.Nsd
+{
+    enum ResultCode
+    {
+        ModuleId       = 141,
+        ErrorCodeShift = 9,
+
+        Success = 0,
+
+        NotImplemented         = (  1 << ErrorCodeShift) | ModuleId,
+        InvalidObject1         = (  3 << ErrorCodeShift) | ModuleId,
+        InvalidObject2         = (  4 << ErrorCodeShift) | ModuleId,
+        NullOutputObject       = (  5 << ErrorCodeShift) | ModuleId,
+        SettingsNotLoaded      = (  6 << ErrorCodeShift) | ModuleId,
+        InvalidArgument        = (  8 << ErrorCodeShift) | ModuleId,
+        SettingsNotInitialized = ( 10 << ErrorCodeShift) | ModuleId,
+        ServiceNotInitialized  = (400 << ErrorCodeShift) | ModuleId,
+    }
+}