Update the Validation implementation starting with the fixes for the following issues:
XERCESJ-1592 - schema validation incorrectly treating single character outside of BMP as two characters
XERCESJ-1646 - Report warning when the maxLength limit is exceeded in an enumeration
XERCESJ-1592 introduced a system property called org.apache.xerces.impl.dv.xs.useCodePointCountForStringLength that may be added to the JDK as is so that the feature is supported.
Other than the above, we may also merge relevant minor changes.