[1.11] Add canApplyAtEnchantmentTable to Item (#3463)

Allowing increased control of which enchantments can be put on an item over Vanilla's hard-coded item type checks.
Render enchantment buttons disabled when the item is enchantable but the enchantability requirement is not met on lower levels.

src/test/java/net/minecraftforge/test/CanApplyAtEnchantingTableTest.java

@@ -0,0 +1,44 @@
+package net.minecraftforge.test;
+
+import net.minecraft.enchantment.Enchantment;
+import net.minecraft.init.Enchantments;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
+import net.minecraftforge.fml.common.registry.GameRegistry;
+
+@Mod(modid="canapplyatenchantingtabletest", name="CanApplyAtEnchantingTableTest", version="0.0.0")
+public class CanApplyAtEnchantingTableTest
+{
+    public static final boolean ENABLE = true;
+
+    public static final Item testItem = new Item()
+    {
+        public boolean isItemTool(ItemStack stack)
+        {
+            return true;
+        }
+
+        @Override
+        public int getItemEnchantability()
+        {
+            return 30;
+        }
+
+        @Override
+        public boolean canApplyAtEnchantingTable(ItemStack stack, Enchantment enchantment)
+        {
+            return super.canApplyAtEnchantingTable(stack, enchantment) || enchantment == Enchantments.FORTUNE;
+        }
+    };
+
+    @Mod.EventHandler
+    public void preInit(FMLPreInitializationEvent event)
+    {
+        if(ENABLE)
+        {
+            GameRegistry.register(testItem.setRegistryName("test_item").setUnlocalizedName("FortuneEnchantableOnly").setMaxStackSize(1));
+        }
+    }
+}