Implement enchant item action

[Pablete1234]

Works similar to replace-item action, but instead of replacing the item enchants it with a level which can be variables/formulas

<enchant-item enchantment="efficiency" level="some_var+1" ignore-metadata="true">
  <find material="diamond_pickaxe"/>
</enchant-item>

The inner element find is an item definition of what to search for in the inventory. Works the same as replace-item, where you can define extra item matching attributes like ignore-metadata and such.

Ontop of that you have the attributes:
enchantment the enchantment to apply
level a formula that says what level. Like all formulas it can be just a constant too like level="5"