[focusgroup] Research issue for patterns incompatible with multi segment model

[sb3nder]

This is to collect research on keyboard patterns incompatible with the default focusgroup multi-segment model.
For now, only patterns or sub-patterns related to the following roles:
toolbar, tablist, radiogroup, listbox, menu, and menubar.

[sb3nder]

ARIA APG Experimental Example of Tabs with Action Buttons:
https://www.w3.org/WAI/ARIA/apg/patterns/tabs/examples/tabs-actions/

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Discord side panel:

[sb3nder]

Also, selection follow focus is a pattern that is compatible with focusgroup, but it can be broken fairly easily if a second segment appears - for example, by opening an opted-out popover in the middle of the group.

FWIW, Safari's radiogroup is multi-segmented when there isn't a checked radio, but if one is checked, it becomes single-segment.