Ability to select `mvnd` for builds

[jglick]

NetBeans bundles a copy of Maven which is used out of the box, but you can also select https://github.com/apache/maven-mvnd as a drop-in replacement as of apache/netbeans#3210. I have not found a way to do the same in this extension, though the first line of the output looks the same as it would be in NetBeans:

cd /path/to/module; JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64 /home/jglick/.vscode/extensions/oracle.oracle-java-22.0.0/nbcode/java/maven/bin/mvn.sh -Dtest=pkg.TheTest --no-transfer-progress process-test-classes surefire:test

mvnd is much faster for incremental development so it is nice to be able to use it, at least until its features are upstreamed into Maven proper.