[client] main: if spice is in use check the guest uuid matches

If the guest supports sending us it's UUID and PureSpice has also
reported the guest's UUID, check them to see if the user has
accidentially connected to the wrong spice socket.

client/src/main.h

@@ -72,6 +72,11 @@ struct AppState
   bool                         dsInitialized;
   bool                         jitRender;
 
+  uint8_t spiceUUID[16];
+  bool    spiceUUIDValid;
+  uint8_t guestUUID[16];
+  bool    guestUUIDValid;
+
   bool                 stopVideo;
   bool                 ignoreInput;
   bool                 escapeActive;