[IcEmptyState] - image and actions slots do not show content

[ad9242]

Summary of the bug

If the image or action slots are initially empty and content is later added, then the content is not visible

🪜 How to reproduce

1. Go to stackblitz example
2. see no slotted content is visible
3. click on the button
4. See only the content in the heading, subheading and body slots is visible. The content in actions and image slots is not visible

the showing\hiding works if all slots have content initially

🧐 Expected behaviour

The content in all slots should be visible if changed from initially empty

📝 Acceptance Criteria

The following applies to all slots in the component

Given a slot is initially empty When content is added to the slot Then the content should be visible