[Feature request]: Element highlighting in addon-interactions

[yannbf]

Ps: This feature should be implemented by a core Storybook maintainer in collaboration with a designer.
Ps²: This issue is mostly a draft on what the idea should be. It should be discussed further with the team.

Context

Addon interactions provides a list of test steps which get executed either automatically or upon click.

However, users might want to know exactly which element is selected in the steps, for easier debuggability. Here's an example of clicking on a "target" icon to see which element is the target of password1.

Desired behavior

Whenever applicable, users should have an option to highlight the element which was interacted with in each test step.

• Clicking on the target icon should highlight the element;
• Clicking on another target should clear the highlight of the previous element, and highlight the next one;
• There should be a way to clear all highlights

Example:

Prior art

There's work which was done prior to this issue, in a closed PR that can serve as inspiration:
#18700