Add a way for apps to know they had been installed via Winget

[kilasuit]

Relevant area(s)

WinGet CLI

Description of the new feature / enhancement

To remove issues like seen regularly in the PowerShell repo that there is a new version released to github but not yet published to winget's repository

Proposed technical implementation details

Perhaps via an Env Var or a Registry setting or something similar

[kilasuit]

@SteveL-MSFT - this would help in the there is a new version of PowerShell notification at start up

[kilasuit]

@denelon I'd be happy to chat further on this