Add tab stops for search result list items

[canadaduane]

Currently, if I hit Ctrl+F to visit the search bar, then search for an app, I see a list of apps returned. However, there doesn't seem to be a way to get to the desired app in the search result list via the keyboard. By pressing the "Tab" key, I can move focus from the search bar to all of the UI elements around the search results, but no way to get to the results themselves.