prepo: Implement calls of IPrepoService (#830)

* prepo: Implement calls of IPrepoService

- Implement `SaveReportOld`, `SaveReportWithUserOld`, `SaveReport`, `SaveReportWithUser` not accurate by RE (except for result codes). It's  here to do something with the data since we will never use the `Play Report` sent by the game. So it's better than just a stub.
- Fix a typo in `ldn` result code.

Close #807

* Add a processing method

* Address some comments

* remove unneeded using

* Resolve requested changes

* Typo

* Update IPrepoService.cs

Ryujinx.HLE/HOS/Services/Ldn/ResultCode.cs

@@ -11,6 +11,6 @@ namespace Ryujinx.HLE.HOS.Services.Ldn
         InvalidState    = (32 << ErrorCodeShift) | ModuleId,
         Unknown1        = (48 << ErrorCodeShift) | ModuleId,
         InvalidArgument = (96 << ErrorCodeShift) | ModuleId,
-        InvalidOjbect   = (97 << ErrorCodeShift) | ModuleId,
+        InvalidObject   = (97 << ErrorCodeShift) | ModuleId,
     }
 }