Fix Fullscreen/Windowed bug on Mac targets...

…Application could not switch on runtime programmatically between
fullscreen or windowed using stage.displayState =
FULL_SCREEN_INTERACTIVE or stage.displayState = NORMAL anymore on Mac
targets, due to missing escaping SDL_WINDOW_FULLSCREEN test in SDL
2.0.3. Added test case line 270 of SDL_cocawindow.m, and additional
patch build in build.hx. Missing the compiled resulting build.n tho