Better handling of enchantments

CMDBOOK-2341 - Reported by Andy

Currently, you can only add enchantments with the /item and /give command if you enter the exact name from org.bukkit.enchantments.Enchantment. Those names aren't all very logical, and some doesn't correspond well to what they are generally called (Which is why the /enchantments command was added I suppose).

I would like to do something about this, and add an /enchant command in InventoryComponent based off the vanilla Minecraft-command with some improvements. In addition to the command handling there would need to be a way to transform user input to Enchantment-values/IDs.

Is this something you might be interested in? Additionally, I'm unsure as to where to send the PR in terms of the lookup-functions. I feel that it might be better to put this class in package com.sk89q.worldedit.blocks since the rest of the Item and Block-class/functions are there, where it may be used by WorldEdit/WorldGuard as well should there ever be a need to (/searchitem is a possibility).

先阅读 InventoryComponent 以及现有的 /item、/give 和 /enchantments 命令处理逻辑，然后检查 org.bukkit.enchantments.Enchantment 的使用情况。在实现提议的 /enchant 命令和用户输入映射之前，明确查找函数应放置的位置；完成的标准是能够接受用户友好的附魔名称，并以一致的方式解析它们。

由索引模型根据 Issue 内容生成。