Option for item pickup to be disabled in vanish instead of forced

[FigT]

Hi there, so whilst I was trying out RoseStacker I noticed that it disables picking up items in vanish, which is fine for most people, but for vanish plugins that offer features to toggle pickup items via a command, etc - well RoseStacker overrides this.

I think it would be beneficial and easy to add a config option to toggle this functionality or not.

It would be the ItemListener and SettingKey class that needs to be modified.

RoseStacker/Plugin/src/main/java/dev/rosewood/rosestacker/listener/ItemListener.java

Line 87 in 6680e4b

if (StackerUtils.isVanished(player)) {

I'd be fine to make a PR for this (although seems like some dependencies are missing so I can't compile it?)

Thanks!