Bosses' Rise Loot Fix

Some Bosses' Rise bosses die in places where their loot gets lost:

• Nerakyss, the Kraken is made of several bodies, and its real body is hidden under its ship. Its loot spawns under the hull or at the bottom of the ocean, where it gets stuck, despawns or is destroyed.
• Sirok, the Sandworm moves its main body through the sand. If it dies underground, its gauntlet (its only drop) spawns inside the sand.
• Ashlord, the Infernal Dragon leaves fire areas that smelt items lying on the ground.

This mod makes sure none of that loot is ever lost.

For all 5 Bosses' Rise bosses (Kraken, Sandworm, Infernal Dragon, Underworld Knight, Yeti):

• Loot goes straight into the inventory of the player who killed the boss. If no player made the kill, it goes to the last player who hit the boss, otherwise to the nearest player within 128 blocks.
• Full inventory? The rest drops at the player's feet, invulnerable (fire, lava, explosions) and with no despawn timer.
• No player around? The loot is moved to the surface, above where the boss died.
• XP goes directly to the player.
• No duplicate loot: if a boss "dies" twice because of its multiple bodies, the second drop is cancelled.
• Zero cost the rest of the time: the mod only acts when one of these 5 bosses dies.