[Feature Request] Support for downgrading from Java version 1.20.5

[willbe03]

Feature Request

The Problem

In 1.20.5 Mojang changed the way to store items from NBT tags to item components. Any downgrade from 1.20.5 to earlier versions would result in item loss because the older Minecraft would not recognize the new format. I tried to use Amulet to downgrade and the items were lost.

Feature Description

Would like to add support for downgrading from 1.20.5+

Alternatives

Additional context

https://fabricmc.net/2024/04/19/1205.html

I am a programmer myself, but I am not familiar with Minecraft internal implementation on maps and items. If some of you guys can provide some insight on where to start or some helpful tutorial, I can try to come up with a PR myself.

[gentlegiantJGC]

We don't currently have any support for entity or item conversion.
I think the data is just copied as is.
That does look like quite a complicated format to support conversion of.