`disable` field on `Numberinput` settings ignored

[fenhl]

I'm trying to implement #2408. I tried adding the following field to the definition of the world_count setting (which is of type Numberinput), but it doesn't do anything:

        disable        = {
            1: {'settings': ['cross_world_songs', 'cross_world_rewards']},
        },

It seems that the functionality for Numberinput settings to disable other settings is not yet implemented. I tried implementing this myself on the cross-world-shuffle-setting branch but it didn't work and I'm not familiar enough with the GUI code to figure out why.