[icToggleButton] - badge and icon slots do not show content if initially empty

[ad9242]

Summary of the bug

If the badge or icon slots are initially empty and content is later added, then that content is not visible

🪜 How to reproduce

Tell us the steps to reproduce the problem:

1. Go to stackblitz example
2. Click on: the show\hide content button
3. see that nothing is added

if content is initially there, then clicking the button to remove does work, although the size of the button does not change to reflect the icon has been removed

🧐 Expected behaviour

The badge & icon should be visible when added

📝 Acceptance Criteria

If relevant, describe in full detail the different interactions and edge cases that the component or patterns needs to fulfil.

Given a toggle button has an empty icon slot When content is added to the slot Then the content should be visible

Given a toggle button has an empty badge slot When content is added to the slot Then the content should be visible

Additional info

tests should be added