Fix `Slider` reinitialization in Storyblok preview

[julrich]

When changing the Slider-content, e.g. adding a slide, the component most of the time ends up in a defective state. Probably needs to be "re-initialized" on the client side. Should only be needed in the preview context in Storyblok.

This might also apply to other components or features, specifically where changes by an editor influence / add markup that gets into components already having initialized client-side code. Should check for other such instances.