Support licenses for Microsoft Store Apps (offline installation)

[denelon]

Description of the new feature / enhancement

The XML namespace for license files is:
xmlns="urn:schemas-microsoft-com:windows:store:licensing:ls"

As we work towards:

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

We need a mechanism for using WinGet to install packages requiring the license in an environment where external connectivity is limited.

This primarily applies to UWP (Universal Windows Platform) Apps. This is likely something that would apply only to MSIX as an installer type and would be excluded by policy from the WinGet community repository. For enterprise use, there would either be a local manifest able to specify the license to apply, or a private REST source able to serve the URL to the license.

Proposed technical implementation details

No response