Use recommended storage locations for app and user data

[danielniccoli]

On Windows, .NET 6 is putting application data directly in the user profile at $env:userprofile\.dotnet. This violates Microsoft recommendations for Windows operating systems and should be moved to the recommended locations.

A selection of recommended storage locations are

• ApplicationData (roaming)
• LocalApplicationData (non-roaming e.g., Local/LocalLow)
• CommonApplicationData (non-roaming)
• CommonProgramFiles (non-roaming)

Source and details about recommended storage locations:
https://docs.microsoft.com/en-us/dotnet/api/system.environment.specialfolder?view=net-6.0

[eiriktsarpalis]

cc @wli3 @dsplaisted

[deeprobin]

I see it the same way.
In my opinion, .dotnet would be "fine" when it comes to configuration files, similar to .ssh.

The same applies to NuGet packages. These are stored in the user directory under .nuget. But I think that concerns a different team.

It might be interesting to consider this.
We should just keep in mind that a change here would cause a breaking change and that a migration strategy to the new path should possibly be built into the SDK/setup.

cc @eiriktsarpalis @wli3 @dsplaisted

[dsplaisted]

Yes, we recognize that these folders don't follow the guidelines. I believe this was an oversight in the first version of the .NET SDK. However, I believe that at this point we don't think it's worth trying to change it.