Added ModJSONClassLoader for the DefaultPlatformManager

Added ModJSONClassLoader for the DefaultPlatformManager to fix an issue when running integration tests using module.links.

When running integration tests with maven or gradle, the platformClassLoader potentially has all provided/test scoped dependencies added to the class path.  If there are vert.x modules added, the wrong mod.json was being picked up.  The ModJSONClassLoader overrides getResources to use the provided urls first.