Find multiple packages from the `msstore` catalog in a single query using the COM API

Description of the new feature / enhancement

Today we can request multiple packages from the predefined winget catalog in a single query (using a selector with multiple filters: id={id}). The same query is not supported for the predefined msstore catalog. Instead, only one PID can be fetched at a time.

var options = CreateFindPackagesOptions();
foreach (var packageId in packageIdSet)
{
    var filter = CreatePackageMatchFilter();
    filter.Field = PackageMatchField.Id;
    filter.Option = PackageFieldMatchOption.Equals;
    filter.Value = packageId;
    options.Selectors.Add(filter);
}

// var catalog = 'winget'   => Allows finding multiple packages in a single query
// var catalog = 'msstore'  => Only one package will be fetched
var findResult = await catalog.FindPackagesAsync(options);

Proposed technical implementation details

From the COM API, add support for bulk fetching packages/applications from the msstore catalog

Start by tracing the COM API implementation of Catalog.FindPackagesAsync and how selector filters are handled for the predefined msstore catalog. Compare that path with the winget catalog behavior shown in the issue. Done means multiple ID selectors return all matching msstore packages in one query, with the existing single-package behavior preserved.