Add configuration for enchantment application

[MartijnMuijsers]

A configuration option like follows:

allowed_enchantment_changes:
  anvil:
  - type: ELYTRA
    enchantment: MENDING
    result: deny
  - type: BOW
    enchantment: LOOTING
    result: allow
  - type: *
    enchantment: CURSE_OF_VANISHING
    result: allow
  enchantment_table: []
  villager_trade: []
  generated_loot:
  - type: GOLDEN_SHOVEL
    enchantment: FIRE_ASPECT
    result: allow

If I were to submit a PR for this, would it be accepted?

[sph432]

How should this handle accepted and unaccepted enchant combos?
Be advised that we already have:

settings:
   ...
  enchantment:
    allow-infinity-and-mending-together: true
    allow-infinity-on-crossbow: true
    allow-unsafe-enchants: true

Modifying base item attributes in a similar manner would be awesome as well.

[MartijnMuijsers]

It would not handle combos at all. It only decides which enchantments could be added to which item (per method). There is already server code for whether an item can be enchanted with a given enchantment, and that would be modified. E.g. it would be impossible to add both sharpness and bane of arthropods on a shovel if both are allowed using this method, since that check for combo is completely independent.

It may be that someone desires that they can add sharpness to tridents but it should not be compatible with impaling. That would require a completely separate and independent feature to define the list of incompatible enchantments. Note however that this may not work consistently with the edge case of already existing items or enchanted books with later defined incompatible enchantments.

EDIT: So this feature would generalize over 'allow-infinity-on-crossbow', and make 'allow-unsafe-enchants' more controllable, and the potential feature I mentioned in the second paragraph would generalize over 'allow-infinity-and-mending-together'.

[RhythmicSys]

This would be better suited for a plugin that would be made to handle enchantments exclusively