make use of the width/height attributes for images in the models and components

[reusr1]

with the introduction of headwirecom/peregrine-cms#671 we support extraction of width and height from assets in the sling models. We should make use of this feature in themecleanflex to render sensible defaults to prevent layout shifts and force the browser to save space for the image that will be loaded

possible approaches:

• https://web.dev/browser-level-image-lazy-loading/
• https://css-tricks.com/preventing-content-reflow-from-lazy-loaded-images/

@Felix-Puetz do you know others?

[flx-sta]

Haven't really worked much with a feature like that in the past. There is a vue-lazyload too but that's it

[reusr1]

Haven't really worked much with a feature like that in the past. There is a vue-lazyload too but that's it

we are already using vue-lazyload in themecleanflex