JBukkit 3.0

Totally reworked project with multiple modules for each Minecraft version.
Added missing UnsafeValues implementation.
Rewritten and updated README.md file.
Updated Minecraft 1.20 Java version to 17.
Updated FulmiCollection.
Implemented server#getRecipesFor method.
Fixed many PotionEffectType related methods for versions older than 1.19.
Fixed MockEnchantment initialization error.
Fixed MockItemFactory#getItemMeta not returning null for Material#AIR.
Fixed Equable#compareNull function.
Fixed MockUnsafeValues#toLegacy and MockUnsafeValues#fromLegacy methods.