Flag to simplify remote matching logic

[PartialEq]

This patch is interesting, because it came in 1.21.4 right before mojang made remote matching a complete mess in 1.21.5, did you know it was about to happen? Also, would enabling this flag have any side effects like clients being able to merge an item with nbt with a non nbt item? or is it just for synchronization

[kennytv]

It's mainly for things like ViaVersion and Geyser that may not (easily) be able to calculate or translate item hashes between versions or platforms - I added it after seeing and having to work with the changes from 1.21.5-pre1... that said, the config option is sort of broken at the moment.

It can result in desyncs between server and client, letting the client have wrong predictions that are then fixed by the server with some delay, but yeah it's only for synchronization.