[implemented] PreviewProvisionerItemAsFurniture

[Rhyono]

As it stands, that function is completely private. If you don't want it to be usable anywhere on the go, I'm not petitioning for that, but I would like it if it could at least be allowed at crafting stations with the stipulation that you know the recipe, since I'm assuming it's already used internally by ZOS at stations anyway. It could follow the same rules as GetRecipeResultItemLink which returns an empty string if it is unknown.