DefaultAzureCredential: Re-enable SSO with VSCode on Windows

[billwert]

VisualStudioCodeCredential will depend on a new authentication tool which replaces the Azure Account extension in Visual Studio Code. This tool is not yet built; more details to come. [https://github.com/microsoft/vscode/issues/178740]

Reminder: when added back to DAC, the default failure mode should be CredentialUnavailableException, as with other dev credentials in the chain.

[Kiechlus]

Is there a timeline on this?