added isOp api

By: Tahg <tahgtahv@gmail.com>

paper-api/src/main/java/org/bukkit/entity/Player.java

@@ -15,6 +15,13 @@ public interface Player extends HumanEntity {
      */
     public boolean isOnline();
 
+    /**
+     * Checks if this player is currently op
+     *
+     * @return true if they are online
+     */
+    public boolean isOp();
+
     /**
      * Sends this player a message, which will be displayed in their chat
      *