WinHost: Add SimplePointer support
Catch WM mouse events and expose them via the SimplePointer protocol.
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Andrew Fish <afish@apple.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Marvin Haeuser <mhaeuser@outlook.de>