UI: Render the panel in JSX (but hidden) when inactive

[ndelangen]

What I did

• I added a prop hidden to the container component used for the Panel.
• A wrapped the content in another one of those wrappers, because that seemed like the easiest way to get this done quick. I didn't want to make changes all over the place at this time.

I could remove the double container, but I'd have to touch something like 10 components and possibly a similar number of story files (add decorators if needed).
I opted not to do that right now.

How to test

• open storybook in the repo
• open the actions panel
• refresh the page
• the visual tests addon panel should not be shown
• assert that state does get set (easy way to verify is to look at the network tab)