Snow Golem Improvements

The Snow Golem has always been a pretty useless golem, and while that may be an intended feature, I think improving it would encourage more players to build and use them. To start, I believe that its health pool should be increased to 12-16 HP, so its at least able to tank a few more hits than it can with the 4 HP it currently has. Another way to make it useful is to have it heal gradually in cold biomes, at a rate on par with regeneration 1, and to have that rate of healing increase when it starts to snow, as the snow will add lost mass back to the Snow Golem's body. Furthermore, snowballs shot by the Snow Golem should be able to slowly freeze the mobs they hit, with each snowball that successfully hits the mob cooling it down to the point that it begins to take freezing damage. Finally, the Snow Golem should be able to circle its opponent while maintaining distance from it to shoot snowballs, so that the Snow Golem is a harder target for ranged mobs to hit.