Implement a ReactOS Qubes domain and hypervisor kernel

Qubes team wants to work with ReactOS in order to run Windows applications seamlessly and efficiently within Qubes domains. (Corresponding issue on their part: <https://github.com/QubesOS/qubes-issues/issues/2809>)
Requirements:
*Seamless GUI integration
*Should be no less performant than equivalent domains with X11
*All Qubes tools, once ported to Windows API, should work
*Filesystem namespacing/overlay/other isolation techniques (User data should be well-separated in a ReactOS Qubes domain)