simplify extraction of plugin settings for Dist::Zilla plugin authors

 Dist::Zilla::Util::ConfigDumper contains a utility function for use
 within the Dist::Zilla plugin ecosystem, to simplify extraction of
 plugin settings for plugin authors, in order for plugins like
 Dist::Zilla::Plugin::MetaConfig to expose those values to consumers.
 .
 Primarily, it specializes in:
 .
   * Making propagating configuration from the plugins inheritance
     hierarchy nearly foolproof.
   * Providing simple interfaces to extract values of lists of named
     methods or accessors
   * Providing a way to intelligently and easily probe the value of lazy
     attributes without triggering their vivification.