Cold Biome Revamp

It's been 7 years since the frostburn update (1.10) and the cold biomes feel pretty empty.

Some ideas for an update include:

-Glaciers, which could be a new ocean biome with a thick layer of ice on top.

-Ice caves, which could spawn in cold biomes with icicles similar to dripstone.

-Blizzards, which could happen occasionally instead of regular snow.