refs https://github.com/TryGhost/Ghost/issues/9505
- Card menu style refinements
- Toolbar style refinements
- Unifying toolbar, link tooltip and link toolbar size and position
- Making link input the same size as text toolbar
- Fix single element position in toolbar
- Making toolbars darker
refs https://github.com/TryGhost/Ghost/issues/9505
- disable `mobiledoc-kit`'s built-in link tooltip
- add `{{koenig-link-toolbar}}` component
- shows toolbar above a link when it is hovered with the mouse
- hides toolbar when a link isn't hovered
- has a clickable link with the URL, opens in a new tab
- edit button switches display to the link input toolbar
- delete button removes link markup from the link