[FancyZones] Update primary desktop data on virtual desktop switch

[vldmr11080]

Summary of the Pull Request

1. If user never made a new virtual desktop, there will be no information about virtual desktop id in the registry, and zeroed-GUID will be used. Migrate persisted information for zeroed-GUID in primary desktop when virtual desktop switch occurs.
2. Don't use IVirtualDesktopManager::GetWindowDesktopId on GetForegroundWindow during initialization. If PowerToys start right away when system starts, GetForegroundWindow might not contain valid HWND, and we could end up with zeroed-GUID.

PR Checklist

• Applies to: Fancy Zones not saved, reset every reboot #7790 [FancyZones] zeroed guid is not handled correctly #7011
• CLA signed. If not, go over here and sign the CLA

Validation Steps Performed

1. Clear the registry (both Software\Microsoft\Windows\CurrentVersion\Explorer\SessionInfo\\VirtualDesktops and Software\Microsoft\Windows\CurrentVersion\Explorer\VirtualDesktops) and persisted FancyZones settings (C:\Users<user-name>\AppData\Local\Microsoft\PowerToys\FancyZones), reboot the machine.
2. Start PowerToys and apply either template or custom layout on primary desktop.
3. Verify that layout information is persisted, and zeroed GUID is used to define primary desktop.
4. Create new virtual desktop.
5. Verify that layout information for primary desktop is preserved, but GUID is updated to the real one.

[vldmr11080]

@enricogior @stefansjfw One possible option, that we should consider is when window is created (FancyZones::WindowCreated callback) we do the check if we still have zeroed GUID, and if that is the case we migrate it based on IVirtualDesktopManager::GetWindowDesktopId and HWND of that newly created window. Creation of new window is something that will happen right as system is started, which means we would migrate primary desktop data quite quickly. Example:

// IFancyZonesCallback
IFACEMETHODIMP_(void)
FancyZones::WindowCreated(HWND window) noexcept
{
    auto& fancyZonesData = FancyZonesDataInstance();
    if (!fancyZonesData.HasValidPrimaryDesktopId())
    {
        GUID desktopId{};
        if (VirtualDesktopUtils::GetWindowDesktopId(window, &desktopId))
        {
            fancyZonesData.UpdatePrimaryDesktopData(desktopId);
        }
    }
    ...
}

I'm aware that this method is called quite often, however check HasValidPrimaryDesktopId is fairly simple, and code within if statement will be called only once.

[enricogior]

@vldmr11080
can you add

L"Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\SessionInfo\\%d\\VirtualDesktops"

to

namespace NonLocalizable
{
    const wchar_t RegCurrentVirtualDesktop[] = L"CurrentVirtualDesktop";
    const wchar_t RegVirtualDesktopIds[] = L"VirtualDesktopIDs";
    const wchar_t RegKeyVirtualDesktops[] = L"Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\VirtualDesktops";
}

[enricogior]

Did some testing and the changes work as expected.