MXParser not failing when space is missing in xml declaration

[belingueres]

Discovered with the help of https://github.com/belingueres/xml-conformance

MXParser fails on parts of the W3C XML Conformance Test Suite.

In this issue, it is failing ibm24n02.xml from "IBM XML Conformance Test Suite - Production 24" (see https://github.com/belingueres/xml-conformance/blob/main/src/test/resources/xmlconf/ibm/ibm_oasis_not-wf.xml) regarding the xml declaration as the first line of the file. It should fail if there is no space between xml and version, like: <?xmlversion='1.0'?>