Manifest schema field for downloadable Microsoft Store packages

[denelon]

Description of the new feature / enhancement

I want to be able to download applications from the Microsoft Store for offline installation. Some of these packages are listed as not downloadable by the publisher/ISV (Independent Software Vendor).

The manifest should indicate when these packages are not available for offline download.

Related Features:

• Officially support downloading signed appx packages from the Store for distribution via own website #578
• winget download #658

Proposed technical implementation details

Optional manifest key "downloadCommandProhibited"
If the key is present with the value "true" then the client will not allow the user to download the package or the license from the Microsoft Store.

The absence of the key or the presence of the key set to "false" means that download is allowed.

By policy, the winget-pkgs repository would not allow the field to be added unless the publisher is a "verified developer". REST servers will have the ability to include the key based on their own policies.