WinRT: Replace custom ClassFactory with WIL CppWinRTClassFactory

[forderud]

Underlying implementation: https://github.com/microsoft/wil/blob/master/include/wil/cppwinrt_register_com_server.h

PROBLEM: wil::register_com_server doesn't seem to pick up the COM class ID as intended. It instead detects the COM interface GUID when calling CoRegisterClassObject.

Upstream issue reports

• WIL bugfix: COM server refactor and improvements microsoft/wil#537
• WIL enhancement request: Use CppWinRTClassFactory to implement DllGetClassObject? microsoft/wil#534

COM class GUID implementation notes

namespace winrt::impl
    template <typename T>
    inline constexpr guid guid_v{ __uuidof(T) };

    template <typename T, typename = std::void_t<>>
    struct default_interface
    {
        using type = T;
    };
}

WINRT_EXPORT namespace winrt
{
    template <typename T>
    using default_interface = typename impl::default_interface<T>::type;

    template <typename T>
    constexpr guid const& guid_of() noexcept
    {
        return impl::guid_v<default_interface<T>>;
    }
}