Overhaul zoom transitions

[EnnuiL]

I have to admit: despite being a pioneer of some sorts (or at least the one who has popularized them), Ok Zoomer's zoom transitions have been overshadowed by a certain competitor's take on it, which I consider to be pretty gimmicky with its many curve options! Except that thanks to the element of time being accounted, it means that when zooming out, it will never feel too fast; So it looks like we'll have to one-up those!

I should note that while adding curves and such would be neat, I don't think I'll abandon the Vanilla-like "Smooth" mode, since I still think it's useful for things like imitating a spyglass and such; The "Linear" mode, however, might be one that's long overdue a revamp