Describe the bug
Because tooltips do not disappear when they are hovered over, and because they now overlap the thing they are showing tips for, it's possible to lose the hover state of the thing the tooltip is highlighting.

I think this might be a regression. I don't remember tooltips being so deep into the button in previous versions of Gutenberg.

To Reproduce
Steps to reproduce the behavior:

1. Compose a new post
2. Hover over a toolbar button for a few seconds
3. Hover over the tooltip when it appears
4. Button hover state is lost

Expected behavior
I expect the tooltip to not overlap the thing being hovered over.

(I also expect tooltips to be more timid than Gutenberg's; they feel too persistent, and take too much focus and attention away.)

Screenshots

Desktop (please complete the following information):

• OS: macOS
• Browser: any
• Version: latest

Additional context

• WordPress 5.0 RC 1