return the title used for InventoryMenu

Author: Faithcaio

src/main/java/org/spongepowered/api/item/inventory/menu/InventoryMenu.java

@@ -78,6 +78,13 @@ static InventoryMenu of(ViewableInventory inventory) {
      */
     void setTitle(Component title);
 
+    /**
+     * Returns the title of this menu if set.
+     *
+     * @return the title of this menu if set.
+     */
+    Optional<Component> title();
+
     /**
      * Registers click callbacks. Unregisters previously registered handler of the same type.
      * <p>Return false in the handler to prevent changes.</p>