Custom Default Item Components & Custom Item "Presets"

I think Datapacks should have a directory (like `datapack_name/items/`) where each item will have its default components, so they are easily changable via datapacks:

For example, name_tag will have `name_tag.json`:

{
  "minecraft:attribute_modifiers": [],
  "minecraft:break_sound": "minecraft:entity.item.break",
  "minecraft:enchantments": {},
  "minecraft:item_model": "minecraft:name_tag",
  "minecraft:item_name": { "translate": "item.minecraft.name_tag"},
  "minecraft:lore": [],
  "minecraft:max_stack_size": 64,
  "minecraft:rarity": "common",
  "minecraft:repair_cost": 0,
  "minecraft:swing_animation": {},
  "minecraft:tooltip_display": {},
  "minecraft:use_effects": {}
}

In order to decrease the average file size, it could use a parents system, so instead of the aformentioned, name_tag.json will be:

{
  "parent": "minecraft:generic"
  "minecraft:item_model": "minecraft:name_tag",
  "minecraft:item_name": {"translate": "item.minecraft.name_tag"}
}

With generic.json having the rest of the components.

This will also lead to the ability of creating custom item "presets" using datapacks using the same format. They won't be real new items (will still be displayed as their Minecraft's parent), but it'll be a shortcut in /give or loot tables or creative mode tabs.