Test Windows specific event code in pollControls in MyOpenGLView.m to see if workarounds still needed with SDL3

[mcarans]

This cleanup step is needed before making any major SDL3 changes to event handling otherwise the code will be a mess

1. Leave all input events in SDL_PollEvent().
2. Remove SDL1.2 workarounds one at a time, testing on Windows and Linux after each removal.
3. Replace platform-specific branches with SDL3 APIs wherever SDL3 now provides the abstraction.
4. Keep OS-specific code only where using platform APIs is absolutely necessary