qml: Update components design and focus box

The following MR updates the following components according to the most recent design discussions:

• GridItem
• TableViewDelegate
• BannerTabButotn
• IconToolButton
• DiscoverUrlDisplay
• TabButtonExt
• TextToolButon
• SortControl

It also adds BackgroundFocus that implements the proper focus rectangle for everyone and FocusBackground becomes BackgroundHover now that the focus component is separate from the background.