Add Nullscape support to End Fishing

[catter1]

Currently, End Fishing only supports the Vanilla biomes. This PR adds support for Nullscape biomes - meaning loot can be gained by fishing in Nullscape's biomes. This is also important, since Nullscape prevents a couple of vanilla end biomes from generating.

History

This was previously discussed over a year ago, but it was not easily possible due to how End Fishing is set up. Now that it is possible to reference biome tags in loot tables, this idea is possible (and can be expanded to other custom end biomes if needed in the future).

Implementation

Three new biome tags were made, following the gm4_end_fishing:nullscape/[biome] schema. These tags reference the respective Nullscape biome, setting required to false. Then the loot tables reference the tags as they would any other vanilla end biome.

Nullscape Biome Loot

• Shadowlands - Copies the End Midlands loot distribution, since End Midlands does not generate in Nullscape
• Void Barrens - Copies the End Barrens loot distribution, since End Barrens does not generate in Nullscape
• Crystal Peaks - Has the default loot distribution, except:
  • Valuables - Obsidian is replaced with Crying Obsidian, and added an extra Amethyst Block entry
  • Scattered Treasure - Made Captain's Wings slightly more common (since it's a mountain biome)

Note

While working on the loot tables, I noticed that Captain's Wings (elytra) was an inline definition in the scattered_treasure loot table. Instead of making a new PR for it, I just moved it to gm4_end_fishing:items/captains_wings (just like ravaged_wings already is) in bb4c0aa. This can be reverted if for some reason it is not wanted.

[misode]

I haven't tested this in-game, but the changes look good!

[misode]

I tested this in-game with Nullscape and can confirm it works. I made some additional commits to cleanup and simplify the loot tables, but they should be equivalent.