Sanitize urls : privacy, read more and source (defense in depth)

The idea is to be sure it's an url with an http(s):// scheme or internal url. 


```
function sanitizeUrl(url) {
    try {
        const u = new URL(url, document.baseURI);

        if (
            u.protocol === 'http:' ||
            u.protocol === 'https:'
        ) {
            return u.href;
        }
    } catch(e) {}

    return '';
}

```