Dialog
Parameters
player
The player that will see the dialog
title
The title of the dialog. If null it will be empty. (Defaults to null)
subtitle
The subtitle of the dialog. If null it will be empty. (Defaults to null)
actionbar
The actionbar of the dialog. If null it will be empty. (Defaults to null)
on Close
The function that will be called when the player closes the dialog. (Defaults to empty function)