Improve design and accessibility of tooltips

[lkiesow]

Instead of just using the title attribute of DOM objects to show a tooltip, it would be great to use a tooltip library similar to what we use in Editor or Studio so that we can style the tooltips and, more important, have the tooltips stay over as long as you hover over them with a mouse. This means that they don't automatically close when you try using accessibility tools like a screen magnifier.

Here is an example of how the tooltips look like in the Editor: