Spawn netherite AEs as chestplates when dropped

- When a netherite ArmoredElytra is dropped (death, dispenser, whatever), it will now drop as a netherite chestplate instead of as an elytra. This allows it to not burn in lava and stuff (which is handled client side).

src/main/java/nl/pim16aap2/armoredElytra/ArmoredElytra.java

@@ -4,6 +4,7 @@ import nl.pim16aap2.armoredElytra.handlers.AnvilHandler;
 import nl.pim16aap2.armoredElytra.handlers.CommandHandler;
 import nl.pim16aap2.armoredElytra.handlers.EventHandlers;
 import nl.pim16aap2.armoredElytra.handlers.FlyDurabilityHandler;
+import nl.pim16aap2.armoredElytra.handlers.ItemDropListener;
 import nl.pim16aap2.armoredElytra.handlers.LoginHandler;
 import nl.pim16aap2.armoredElytra.handlers.SmithingTableHandler;
 import nl.pim16aap2.armoredElytra.handlers.Uninstaller;
@@ -102,6 +103,7 @@ public class ArmoredElytra extends JavaPlugin implements Listener
             final Listener creationListener = config.craftingInSmithingTable() ?
                                               new SmithingTableHandler(this) : new AnvilHandler(this);
             Bukkit.getPluginManager().registerEvents(creationListener, this);
+            Bukkit.getPluginManager().registerEvents(new ItemDropListener(this), this);
 
             // Log all allowed enchantments.
             myLogger(Level.INFO, ("Allowed enchantments:"));

src/main/java/nl/pim16aap2/armoredElytra/handlers/ItemDropListener.java

@@ -0,0 +1,88 @@
+package nl.pim16aap2.armoredElytra.handlers;
+
+import nl.pim16aap2.armoredElytra.ArmoredElytra;
+import nl.pim16aap2.armoredElytra.util.ArmorTier;
+import org.bukkit.Material;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityPickupItemEvent;
+import org.bukkit.event.entity.ItemSpawnEvent;
+import org.bukkit.event.inventory.InventoryPickupItemEvent;
+import org.bukkit.inventory.ItemStack;
+
+public class ItemDropListener implements Listener
+{
+    protected final ArmoredElytra plugin;
+
+    public ItemDropListener(final ArmoredElytra plugin)
+    {
+        this.plugin = plugin;
+    }
+
+    /**
+     * Gets a new item to drop by analyzing an item that will be dropped.
+     * <p>
+     * So when dropping an armored elytra of the netherite tier, it will return a netherite chestplate (with the meta
+     * copied over).
+     *
+     * @param itemStack The dropped item to analyze.
+     * @return The new item to drop if it should be changed. If no change is required, null is returned.
+     */
+    private ItemStack getNewDrop(final ItemStack itemStack)
+    {
+        if (itemStack == null || itemStack.getType() != Material.ELYTRA ||
+            plugin.getNbtEditor().getArmorTier(itemStack) != ArmorTier.NETHERITE)
+            return null;
+
+        ItemStack newDrop = new ItemStack(Material.NETHERITE_CHESTPLATE, 1);
+        newDrop.setItemMeta(itemStack.getItemMeta());
+
+        return newDrop;
+    }
+
+    /**
+     * Gets a new item to pick up by analyzing an item that would be picked up.
+     * <p>
+     * So when picking up a placeholder netherite chest plate (as replaced by {@link #getNewDrop(ItemStack)}) it would
+     * return an armored elytra of the netherite tier.
+     *
+     * @param itemStack The picked-up item to analyze.
+     * @return The new item to pick up if it should be changed. If no change is required, null is returned.
+     */
+    private ItemStack getNewPickup(final ItemStack itemStack)
+    {
+        if (itemStack == null || itemStack.getType() != Material.NETHERITE_CHESTPLATE ||
+            plugin.getNbtEditor().getArmorTier(itemStack) != ArmorTier.NETHERITE)
+            return null;
+
+        ItemStack newDrop = new ItemStack(Material.ELYTRA, 1);
+        newDrop.setItemMeta(itemStack.getItemMeta());
+
+        return newDrop;
+    }
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
+    public void onDrop(final ItemSpawnEvent event)
+    {
+        final ItemStack newDrop = getNewDrop(event.getEntity().getItemStack());
+        if (newDrop != null)
+            event.getEntity().setItemStack(newDrop);
+    }
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
+    public void onEntityPickup(EntityPickupItemEvent event)
+    {
+        final ItemStack newPickup = getNewPickup(event.getItem().getItemStack());
+        if (newPickup != null)
+            event.getItem().setItemStack(newPickup);
+    }
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
+    public void onInventoryPickup(InventoryPickupItemEvent event)
+    {
+        final ItemStack newPickup = getNewPickup(event.getItem().getItemStack());
+        if (newPickup != null)
+            event.getItem().setItemStack(newPickup);
+    }
+}

src/main/java/nl/pim16aap2/armoredElytra/nbtEditor/NBTEditor.java

@@ -23,9 +23,6 @@ public class NBTEditor implements INBTEditor
     {
     }
 
-    /**
-     * {@inheritDoc}
-     */
     @Override
     public ItemStack addArmorNBTTags(ItemStack item, ArmorTier armorTier, boolean unbreakable)
     {
@@ -65,9 +62,6 @@ public class NBTEditor implements INBTEditor
         meta.addAttributeModifier(attribute, attributeModifier);
     }
 
-    /**
-     * {@inheritDoc}
-     */
     @Override
     public ArmorTier getArmorTier(ItemStack item)
     {