feat(SerializableItemStack): Allow setting item instrument tag.

[WaveOfWaves]

When using goat_horn as the base item, you currently can't change the default instrument sound. Adding playSound to an itemRightClick action plays item.goat_horn.sound.0 plus whatever sound is added through playSound. Using paper as the base item prevents the sound/instrument from being shown in the item tooltip. Adding an item instrument tag would solve both of these problems.

Suggested yaml syntax:

set.item:
  item:
    type: minecraft:goat_horn
    instrument: sing_goat_horn

[0ffz]

We also discussed potentially directly transforming the item syntax to json and creating vanilla items this way, however I think it's potentially worth maintaining feature by feature to keep the configs cleaner. Worth investigating.

[Boy0000]

the datacomponent PR does most of the component stuff and 1.21.3 so