Context: https://linear.app/comm/issue/ENG-794#comment-a3728358
In the past, there was an ellipsis button that when clicked would reveal a menu with possible actions ("Create sidebar", "Reply"). In the future, the icons for each action will be displayed in a row. But, we still want to display an informative "alt text" tooltip when the icons are hovered over. In this diff we're making the tooltip content static and triggering it `onMouseEnter` instead of `onClick`