[LoginOverlay] Events on slotted content do not work

[sissbruecker]

When adding a button with a click handler to the login overlay's footer or custom form area, then the handler is never called when clicking the button:

<LoginOverlay opened>
    <div slot="footer">
        <button onClick={() => console.log('click')}>foo</button>
    </div>
</LoginOverlay>

It looks like the web component contains some logic for teleporting the content from the base element to the overlay, thus manipulating the DOM rendered by React, which might then interfere with React's event system.

Instead we should probably use whatever solution other React components like Dialog use to teleport the content. Might also be an opportunity to add a more React-like API where a JSX element is passed as a prop for example.