Groovysh DocCommand improvements

A number of parts of the groovysh DocCommand haven't been updated to account for recent JDK versions:

• The URLs used when firing up the browser should be https not http
• The URLs for Java classes for JDK9+ don't add in the module, so aren't found
• There is no easy way to access primitive groovy-jdk enhancements
• groovy and org.codehaus.groovy package prefixs are looked for in the gapi but not the org.apache.groovy prefix
• groovy-jdk enhancements for groovy classes aren't browsed
• access to groovy-jdk enhancements for primitives is buggy

The proposal will be to remove some of the limitations and allow an optional module to be specified when entering the class, e.g.:

groovysh> :doc java.base java.util.List

with the default being java.base