[client] spice: add option to ignore the windows key

If active this will prevent the client from sending keyboard events for
the windows key. The idea is to allow people to keep the windows key
bound to their WMs default action without causing the Windows start menu
to open

client/src/main.h

@@ -121,6 +121,7 @@ struct AppParams
   bool         grabKeyboard;
   bool         grabKeyboardOnFocus;
   SDL_Scancode escapeKey;
+  bool         ignoreWindowsKeys;
   bool         showAlerts;
   bool         captureOnStart;
   bool         quickSplash;