LPS-44635 Use HTML Data Porcessor to normalise HTML.
Revert "LPS-44635 Use HTML Data Porcessor to normalise HTML."

This reverts commit ef60c9d97b592276df117a28ae4e55f50ba84cf4.
LPS-44635 - Avoid adding \\ if br element does not have previous sibling

Gecko based browsers add <br> element after text which is enclosed in elements,
like heading, list elements, etc. We will convert br elements to \\ only if
they don't have previousSibling, aka of they look like this: <p><br></p>