* 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
* Implement ConvertScalingMode properly
* Fix up the naming
* Only values 2 and 4 are allowed
* Return a nullable enum from ConvetScalingMode
* Fix typo on method name
* Use convertedScalingMode