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/Aud/ResultCode.cs

@@ -1,15 +0,0 @@
-namespace Ryujinx.HLE.HOS.Services.Aud
-{
-    enum ResultCode
-    {
-        ModuleId       = 153,
-        ErrorCodeShift = 9,
-
-        Success = 0,
-
-        DeviceNotFound        = (1 << ErrorCodeShift) | ModuleId,
-        UnsupportedRevision   = (2 << ErrorCodeShift) | ModuleId,
-        UnsupportedSampleRate = (3 << ErrorCodeShift) | ModuleId,
-        OpusInvalidInput      = (6 << ErrorCodeShift) | ModuleId
-    }
-}