Through https://jira.ez.no/browse/EZP-24732 (see discussion on the PR) it came out we should not strictly require fell formed XML as an input, but we should rather accept a more relaxed format to lower the requirements for the client-side.

This should be achieved by implementing a kind of input pre-processing that will normalize the given input to what can be accepted by the current converter implementation, meaning proper XML.

This issue is a first step and requires accepting HTML entities as input without defining them in XML DTD.