AJAX without the Drupal FormBase class

AJAX Open buttonDrupal 8 forms are usually classes that inherit from the FormBase class.  The FormBase class provides underlying functionality such as AJAX for Drupal forms.  This article explores how to use only the form API without the FormBase class yet provide a light weight AJAX behavior.  To keep this from getting too complex only buttons and event handling are considered.  While this could be useful on its own it also prov