* 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

* 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

* Vi: Implement ConvertScalingMode

For now, it seems Nintendo just map 1:1 between the two enums.

* Resolve style nits

* Vi: Correct mapping order