Re-exporting sl- components at hot- results in events not triggering

[spwoodcock]

Describe the bug

• Have a hunch that some of the components rely on accessing sl-xxx in some events.
• A good example of a combination of components is: https://shoelace.style/components/dropdown#getting-the-selected-item
• Here when we have hot-dropdown, selecting an element doesn't seem to do anything.
• I am assuming that if it was sl-dropdown this would work.

To Reproduce

• Create a dropdown as above.

Expected behavior

• I'm starting to think we should probably not re-export the low level components.
• Keep a mix of sl-xxx for those, plus hot-xxx for the composite components we create.
• This will mean we need to update the CSS vars too.

[emi420]

I agree that we should not re-export the Shoelace components.

We should keep the theme for Shoelace, there's not need of changing anything there because it's using the 'sl-' prefix.