Investigate and replace `rvest` in favor of a lighter package `xml2`

Nowadays I think `rvest` is just a wrapper around `xml2`. Maybe we can work directly with `xml2`? See `namespace:xml2`

```r
> rvest::read_html
function (x, encoding = "", ..., options = c("RECOVER", "NOERROR",
"NOBLANKS"))
{
UseMethod("read_html")
}

```

_Originally posted by @m7pr in https://github.com/insightsengineering/teal/pull/1127#discussion_r1516082275_