Adding PredicateChoice to Paper API (updated version)

[CPieter]

This PR is an updated version of derverdox's PredicateChoice PR #9996. Since the branch in the old PR was quite outdated I reïmplemented the changes in a new branch, but most of the changes remain the same. Credit of the code should go to derverdox and Machine-Maker.
The feature seems to work fine from my testing but I'm unfamiliar with the Paper API so I please let me know if I missed something.

[lynxplay]

Welcome to paper 🎉
Thank you for updating the PR. I don'T have time for a indepth review rn, but I left some initial easy nitpicks around comments 👍

Will get to a review next week probably

[Doc94]

Hi and welcome to the Paper PR world (well this more a thing can say a Paper Team Member xd)

The paper comments currently just apply to code in patches, its not required in the api,craftbukkit,paper classes.

[CPieter]

I just noticed there is already a PredicateRecipeChoice for potions, with the addition of the PredicateChoice this could be a bit confusing. Maybe it should be renamed to something more clear like a PotionRecipeChoice/PotionPredicateChoice?

[Doc94]

I just noticed there is already a PredicateRecipeChoice for potions, with the addition of the PredicateChoice this could be a bit confusing. Maybe it should be renamed to something more clear like a PotionRecipeChoice/PotionPredicateChoice?

well rename sounds a little breaking i think, maybe this new PredicateChoice can be named ItemPredicateChoice (? or add an extension of RecipeChoice for Potion and move things to that for make clear the diff... but not really sure.

[Machine-Maker]

I just noticed there is already a PredicateRecipeChoice for potions, with the addition of the PredicateChoice this could be a bit confusing. Maybe it should be renamed to something more clear like a PotionRecipeChoice/PotionPredicateChoice?

Since PredicateRecipeChoice isn't public, delete it, and make PotionMix#createPredicateChoice return an instance of the new type. But also deprecate that method, and suggest to use the new method you create.

Here's a great example of what I talked about in my review, suggesting to keep implementation types out of the "api" because we can now just delete PredicateRecipeChoice entirely.

[Machine-Maker]

Looks good, just a few more things. I also opened the PR adding the future alternative to MaterialChoice. Will merge mine in after yours

[CPieter]

Since PredicateRecipeChoice isn't public, delete it, and make PotionMix#createPredicateChoice return an instance of the new type. But also deprecate that method, and suggest to use the new method you create.

Here's a great example of what I talked about in my review, suggesting to keep implementation types out of the "api" because we can now just delete PredicateRecipeChoice entirely.

Most issues with the PR should now be resolved, but I'm not quite sure how to properly replace the PotionMix predicate choice. The new PredicateChoice requires an example stack, but this might not really make sense for use in the PotionMix. I'm hesitant to make the example stack nullable since not having one can break recipes. Maybe the PotionMix update should be left to a seperate PR?