SPIGOT-7309: Add API for jukebox inventories

By: Parker Hawke <hawkeboyz2@hotmail.com>

paper-api/src/main/java/org/bukkit/block/Jukebox.java

@@ -1,14 +1,16 @@
 package org.bukkit.block;
 
 import org.bukkit.Material;
+import org.bukkit.inventory.BlockInventoryHolder;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.JukeboxInventory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
  * Represents a captured state of a jukebox.
  */
-public interface Jukebox extends TileState {
+public interface Jukebox extends TileState, BlockInventoryHolder {
 
     /**
      * Gets the record inserted into the jukebox.
@@ -62,4 +64,19 @@ public interface Jukebox extends TileState {
      * @throws IllegalStateException if this block state is not placed
      */
     public boolean eject();
+
+    /**
+     * @return inventory
+     * @see Container#getInventory()
+     */
+    @NotNull
+    @Override
+    JukeboxInventory getInventory();
+
+    /**
+     * @return snapshot inventory
+     * @see Container#getSnapshotInventory()
+     */
+    @NotNull
+    JukeboxInventory getSnapshotInventory();
 }