Using Toolbar Patterns from the ARIA Authoring Practices Guide for Better Assistive Experience

[ARIA Authoring Practices Guide](https://www.w3.org/WAI/ARIA/apg/patterns/) provide recommendations for accessible experiences for interactive elements. the jupyter menu bars already abide the [menu bar pattern](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/) that allows for arrow key navigation around the menus. as a result, only one element from the menu bar shows in the tab ordering.


the preceding image indicates and #6800 indicate 20 tabs are needed to reach a cell since the toolbars do not abide the suggested [APG toolbar example](https://www.w3.org/WAI/ARIA/apg/patterns/toolbar/). these tab counts include the notebook and cell level toolbars. using the toolbar pattern we could drastically reduce the effort needed to navigate to cells. the recommended toolbar pattern allows focus on the last active element with arrow navigation to other elements.

is this a pattern that jupyter could support?

Begin by reviewing the existing notebook and cell-level toolbar behavior described here and in #6800. Compare their tab and arrow-key focus behavior with the ARIA Authoring Practices Guide toolbar pattern and the existing menubar pattern. Done means agreeing on a concrete implementation scope and reducing unnecessary tab stops while preserving accessible keyboard navigation.

Written by the indexing model from the issue text.