[Bleeding] Implement setCharged and getCharged for WitherSkull. Addresses BUKKIT-3060

By: t00thpick1 <t00thpick1dirko@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftWitherSkull.java

@@ -10,6 +10,16 @@ public class CraftWitherSkull extends CraftFireball implements WitherSkull {
         super(server, entity);
     }
 
+    @Override
+    public void setCharged(boolean charged) {
+        getHandle().a(charged);
+    }
+
+    @Override
+    public boolean isCharged() {
+        return getHandle().f();
+    }
+
     @Override
     public EntityWitherSkull getHandle() {
         return (EntityWitherSkull) entity;