Tabset improvements

[geoffrey-eisenbarth]

With the upcoming refactor of tabs, we should try to support the following:

• start / end + horizontal / vertical tablists, facilitated by <aria-tabset> container element.
• close / reopen tabs
• reorder tabs
• multiple select tabs (idk i what this looks like visually)
• scrolling / wrapping tablists, or tablist reflow or overflow menu
• tabs with actions

[geoffrey-eisenbarth]

In regards to re-orderable / draggable tabs, the following might be helpful:

• https://www.darins.page/articles/screen-readers-drag-drop-1
• https://react-spectrum.adobe.com/blog/drag-and-drop.html
• https://www.tpgi.com/the-road-to-accessible-drag-and-drop-part-1/
• https://www.tpgi.com/the-road-to-accessible-drag-and-drop-part-2/

[geoffrey-eisenbarth]

Regarding tabs with actions:

• Official aria-actions PR
• Current impl markup