upgrade plexus-util 3 to plexus-utils 4 + plexus-xml 3

• Modello generated code for archetype-descriptor and archetype-catalog require Maven 3 XML APIs to read/write XML descriptors => plexus-xml 3 is a key requirement
• plexus-xml 4 is Maven 4 specific, then upgrading plexus-xml from 3 to 4 has to be avoided
• plexus-utils 4 remains useful as code generated by Modello still require a few classes like StringUtils...

this upgrade is a proof of seamless upgrade from plexus-utils 3 to plexus-utils 4 + plexus-xml 3 when XML API are required
MJARSIGNER-71 is the proof when plexus-xml is even not required in the upgrade