Refactoring result codes (#731)

* refactoring result codes

- Add a main enum who can handle some orphalin result codes and the default `ResultCode.Success` one.
- Add sub-enum by services when it's needed.
- Remove some empty line.
- Recast all service calls to ResultCode.
- Remove some unneeded static declaration.
- Delete unused `NvHelper` class.

* NvResult is back

* Fix

Ryujinx.HLE/HOS/Services/Hid/IAppletResource.cs

@@ -16,7 +16,7 @@ namespace Ryujinx.HLE.HOS.Services.Hid
 
         [Command(0)]
         // GetSharedMemoryHandle() -> handle<copy>
-        public long GetSharedMemoryHandle(ServiceCtx context)
+        public ResultCode GetSharedMemoryHandle(ServiceCtx context)
         {
             if (context.Process.HandleTable.GenerateHandle(_hidSharedMem, out int handle) != KernelResult.Success)
             {
@@ -25,7 +25,7 @@ namespace Ryujinx.HLE.HOS.Services.Hid
 
             context.Response.HandleDesc = IpcHandleDesc.MakeCopy(handle);
 
-            return 0;
+            return ResultCode.Success;
         }
     }
 }