{{-- Panel heading copied from Product.vue so the two pages match exactly: title left, filter toggle and add button floated right and pulled up over the title with the same negative margins. $title panel title $addTarget modal id to open, or null for no add button $addTooltip tooltip for the add button $hasFilters whether any filter is currently applied $extra optional extra buttons, each ['target' => modal id, 'tooltip' => ..., 'icon' => glyphicon suffix]. A single button may be passed unwrapped. --}}