Table should style an unselected row when it is right-clicked. Finder uses an inset blue border.
Note: this may require additional information from the backend, to know when the menu is shown/dismissed. InspectorFrontendAPI provides the following:
However, ContextMenu.js has this to say:
// FIXME: Unfortunately, contextMenuCleared is invoked between show and item selected
// so we can't delete last menu object from WI. Fix the contract.
This is definitely worth doing, as we'll want this for TreeOutline as well.