Message 229981 - Python tracker

At one time, ConfigDialog was given a do-nothing Help button.  It was diabled a couple of years ago.  This patch restores it for both config dialogs, displaying a text appropriate for both.  There are separate functions in anticipation of dialog-specific content.  For both, there is the issue of when changes take effect (#22707).  For extensions, there might be extension-specific help (#22705).