ActionBar not clickable in the Actions addon

[domyen]

Describe the bug
This PR #11502 removed the z-index for the ActionBar component. We actually need/use it in the Actions addon.

Video here

To Reproduce
Steps to reproduce the behavior:

1. Go to published Storybook for next
2. Click on button in the canvas tab. Go to actions addon panel.
3. Try to "clear" actions using the button on the bottom right.
4. See that you cannot click on the clear button

Expected behavior
That you can click on the "clear" button.

Screenshots
See video above.

Reverting #11502 should fix this.

[domyen]

This is fixed ✅