Snow Golem Backport

Backports the snow golem from more modern versions of Minecraft to the Better Than Adventure mod. What's the same?

• Snow golems are created by stacking two snow blocks vertically with a pumpkin on top.
• Snow golems throw snowballs at most monsters.
• Snow golems take damage in water blocks.

What's different?

• Snow golems no longer create snow trails to keep obtaining renewable snow more interesting.
• Snow golems no longer die in warm biomes.
• Snow golems now deal one damage when standing on gravel instead of the usual zero similarly to vanilla BTA's snowmen.
• Snow golems now require swords to have their pumpkins taken off instead of shears to be consistent with BTA's pumpkin carving.
• Pumpkinless snow golems can now have carved pumpkins be put on their heads.
• Snow golems now have double their original health. (Two hearts to four hearts)
• Snow golems now drop 1-8 snowballs upon death and if they have a pumpkin on their head they'll drop it as well.