Icon.ExtractAssociatedIcon should return an icons descriptor

[jez9999]

Background and motivation

Right now, the Icon.ExtractAssociatedIcon method can be used to get one and only one of the icons associated with a certain file, but the file is likely to have multiple icons of different sizes and color depths associated with it. I think this method or a new similar method should return some kind of "icons descriptor" where you can iterate through every icon associated with the file specified. I notice some work was done in issue #8929 to add ExtractIcon but that really tackles a different problem of extracting an icon from the file actually containing the icon resource and not a file just associated with it. Basically I want to be able to pass in a .pdf file and get all the icons associated with PDF files on the system.

API Proposal

namespace System.Drawing;

public class Icon
{
    // The existing Extract method.
    public static Icon ExtractAssociatedIcon(string! filePath);

    // New method to get all icons
     public static IconsDescriptor ExtractAssociatedIcons(string! filePath);
}

API Usage

// Get icons descriptor
using IconsDescriptor icons = Icon.ExtractAssociatedIcons(@"C:\Path\To\my.pdf");
// e.g. save all icons to their own file
foreach (var icon in icons.AllIcons) {
    using (var outputFileHandle = getNewIconHandle()) {
        icon.Save(outputFileHandle);
    }
}

Alternative Designs

No response

Risks

No response

Will this feature affect UI controls?

No.