Allow selection/addition of Windows Store Apps

[kimmknight]

As mentioned in issue #89, there are ways to retrieve a list of Windows store apps. Perhaps RemoteApp Tool could have an Add Windows Store App button that brings up a list and lets you select one to be added.

[gengyj16]

It doesn't seem to always end with "!App". One way to list all the app names is as follows.
Reference

$installedapps = get-AppxPackage
foreach ($app in $installedapps)
{
    foreach ($id in (Get-AppxPackageManifest $app).package.applications.application.id)
    {
        $app.packagefamilyname + "!" + $id
    }
}