Adding support for the GraalVM

Hi all,

I'm working on getting
https://www.graalvm.org/native-image/libraries-and-frameworks/ level 1
support for GraalVM for  org.apache.xml.security, any objections,
concerns things I have to  watch out for?

Progress will be tracked here:
https://github.com/oracle/graalvm-reachability-metadata/issues/660

Kind regards

Guust