Upgrade Xerces2 Java to Version 2.12.0

Updating the JDK to Xerces 2.12.0.

Xerces 2.12.0 provides two distributions: "Xerces2 Java 2.12.0" and "Xerces2 Java 2.12.0 (XML Schema 1.1)", refer to Xerces Download at https://xerces.apache.org/mirrors.cgi. Maven only distributes the former as of 4/15/2019. The discussion through Xerces Issue 1695 (https://issues.apache.org/jira/browse/XERCESJ-1695) indicated that the distribution with Schema 1.1 support was not compatible with Xerces 2.11.0. Furthermore, it also has a dependency on Eclipse/PsychoPath. For this upgrade therefore, we will upgrade to regular 2.12.0 release without XML Schema 1.1.