Fishermen Changes

Inspired by: https://www.reddit.com/r/minecraftsuggestions/comments/uy3q0g/make_fishermen_sell_coral_blocks/?utm_source=share&utm_medium=web2x&context=3

Adds:

-Trades for fisher villagers which allow them to sell coral blocks on levels expert and up

-Recipes for making coral blocks from coral (not fans)

That's literally the only things it adds.

Pretty much a QoL (Quality of Life) mod. Not that many features, might make a datapack port someday.