Now use a Map to keep track of individual elements to prevent duplication.
Previously would increment continuously just by switching dropdown options. So users could bypass the requirement to complete starred(*) fields by toggling a dropdown a few times, or by focussing and unfocussing input elements, causing nbSetRequiredKeys++ to increment without limit.
GlobalEventHandlers.onchange only fires when focus is lost. However .oninput fires whenever contents are modified. Original requires "double click" behaviour: first click to deselect the input element, second click to actually click the "Ok" button. Old code results in "Ok" buttons remaining visually disabled thus confusing users even when input elements have been completed
