Add new internal error message for invalid parameters; add validation of input rect in SDL_SetTextInputRect; add test cases for SDL_SetTextInputRect to keyboard suite

src/video/windows/SDL_windowskeyboard.c

@@ -212,6 +212,12 @@ void
 WIN_SetTextInputRect(_THIS, SDL_Rect *rect)
 {
     SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
+    
+    if (!rect) {
+        SDL_InvalidParamError();
+        return;
+    }
+    
     videodata->ime_rect = *rect;
 }