General Consistency Improvements for Ice Caves

Ice Caves are quite a cool concept (pun not intended), but I think there's quite a few ways they could be changed to be more in-line with other cold biomes, as well as their own unique elements:

• Redstone Ore generates more frequently in Ice Caves. This block has a light level, which would give it a dynamic interaction with the biome's icicles
• Strays should not cause Brittle Ice to break, like Frostbites
• Strays should neither be slowed down nor fall through powder snow, like Frostbites
• Drowned should convert into Zombies when submerged in Powder Snow, similar to how Husks convert into Zombies when submerged in water
• Endermites, Silverfish, Rabbits, Foxes, Shulkers, and Vexes should not cause Brittle Ice to break, mirroring their behaviour with powder snow
• Blazes should take increased damage from Ice Balls as they do with Snowballs and the Freezing effect
• Powder snow should generate in ice caves

In sum, I think the above changes would better integrate this new biome into the game.