fix compile on Linux (attempt 2)

[joppiesaus]

I fixed it by changing the type to int32_t, instead of the suggested uint32_t, as glfwGetWindowSize(GLFWwindow* window, int* width, int* height); uses signed ints, therefore it seems to it makes more sense to change it to an int32_t. Plus less things to change to the codebase. Cheers!

(See also #36)

[W2Wizard]

The old PR was totally fine btw, you could have done this change in there but oh well.

[joppiesaus]

I have changed a bunch of stuff. It should be looked at thoroughly. It changes some definitions, int32_ts are changed in favor of uint32_t. This might break existing projects that use MLX42, as the resize hook is also changed, although the fixes should be very simple to apply. Furthermore, one can call mlx_set_window_size with an uint32_t1 above MAX_INT but below unsigned max int value, and it will flip the signs around. Though to be honest, I don't think there are monitors with a size of 2,147+ billion. Same said for mlx_get_monitor_size.

[W2Wizard]

Thought it should just work right out of the gates, instead everything broke. So for now I reverted it.