Increase sulfur pool frequency + slight rework to sulfur pool generation

From what I've seen going around to different sulfur cave biomes the amount of sulfur pools present is very very low even when the biome is fairly big. And whenever they do spawn they tend to be in places you can't find easily (such as behind walls or only visible from little two by two or three holes) and when they do spawn normally the potent sulfur spawns on the very edge of the pool diminishing the sulfur cloud effect that makes the pool unique from regular water pools found everywhere else underground (or they spawn underneath blocks that make the effect not happen at all).

My suggestions would be to increase the rate that sulfur pools spawn in the sulfur caves and reconfigure where the potent sulfur generates in the sulfur pools to be more in the center to avoid their effects being minimized or nonexistent.