The Popup's empty / generic / error / disambiguation "preview" and page preview templates have similar outer divs and LESS. This task encompasses the work to make a new popup template that accepts an unescaped HTML "children" string and update the LESS so that empty / generic / error / disambiguation CSS is in preview.less, page preview LESS is in pagePreview.less, and generic popup LESS is in popup.less.
```lang=jsx
<div class='mwe-popups mwe-popups-type-${ type }' role='tooltip' aria-hidden>
<div class='mwe-popups-container'>
<div class='mw-ui-icon mw-ui-icon-element mw-ui-icon-preview-${ type }'></div>
${ showTitle ? `<strong class='mwe-popups-title'>${ title }</strong>` : '' }
<a href='${ url }' class='mwe-popups-extract'>
<span class='mwe-popups-message'>${ extractMsg }</span>
</a>
<footer>
<a href='${ url }' class='mwe-popups-read-link'>${ linkMsg }</a>
</footer>
</div>
</div>
```
```lang=jsx
<div class='mwe-popups' role='tooltip' aria-hidden>
<div class='mwe-popups-container'>
${ hasThumbnail ? `<a href='${ url }' class='mwe-popups-discreet'></a>` : '' }
<a dir='${ languageDirection }' lang='${ languageCode }' class='mwe-popups-extract' href='${ url }'></a>
<footer>
<a class='mwe-popups-settings-icon mw-ui-icon mw-ui-icon-element mw-ui-icon-popups-settings'></a>
</footer>
</div>
</div>
```