RFR JDK-8165640: Enhance jar tool to allow module-info in versioned directories but not in base in modular multi-release jar files

Hi, Please help review the changes for https://bugs.openjdk.java.net/browse/JDK-8165640 http://cr.openjdk.java.net/~sherman/8146486/webrev There are two changes (1) to use the versioned module-info as the module descriptor to validate the versioned entries, if the root/base "/module-info.class" is missing. (2) -d to print out all available module-info entries, versioned included. Thanks, Sherman