* fix: use an iframe to preserve head and body
* fix: remove unnecessary parsing of html
The contents gets inserted into the DOM during transformHtml, which
is always part of the build pipeline
* fix: pipe contents through iframe
* refactor: use the same code for both transforms
* fix: try to handle test errors better
Co-authored-by: moT01 <20648924+moT01@users.noreply.github.com>