Build the group-header element for an overflow tab-group id, or
undefined when it is not an overflow group.
Build the "Pinned" section header shown above the pinned overflow rows (see AdvancedOverflowRenderParams.pinnedOverflowTabs).
Build a single overflow row for a panel id, or undefined if the panel
no longer exists in the group.
Close the popover.
Restore focus to the chevron trigger (Esc).
Open body in the group's window-bound popover at the chevron anchor.
The overflow tab-group id a panel belongs to, or undefined. Used to
interleave group headers against the filtered set (same rule as free).
Core-provided builders handed to IAdvancedOverflowService.renderOverflow so the module can rebuild the free dropdown body (rows + group headers) in a custom order (search-filtered, MRU-ordered) without re-implementing the row DOM, the group-header DOM, or the window-bound popover open/close. The popover control stays in core so it renders in the correct document for popped-out groups (a
getPopupServiceForGroup(group)-boundPopupService).