Use Shears to control Shelf Mushroom growth stages

Using shears on glow berry vines, weeping vines, twisting vines, and kelp could stop them from growing. This feature could also be implemented for the newly added shelf mushrooms. It would be nice if we could keep some of them permanently small and others permanently large. This would make building and decorating with them much more interesting, while also providing a useful mechanic for parkour map creators.