Fix the DrupalConsole tag generator

This works, but only in the strictest definition. It needs some work.

This adds the --base_class, --image and --multiple options, and improves some of the other options by adding their defaults.

It's now failing with the following:

Fatal error: Call to a member function getPath() on null in phar:///Users/myaccount/.composer/vendor/drupal/console/bin/console/src/Helper/SiteHelper.php on line 178

No more errors, because I forgot an argument to the generator function call.

One remaining question - is there a better way to get a boolean from the user than doing this?

Whether this meta tag will allow multiple values:
  [0] FALSE
  [1] TRUE
 > 

This fixes the tag generator so it includes the 'image' and 'multiple' options.

Trying that again.

Well that's quite silly, it's complaining about the formatting of a twig file because it's invalid PHP code. It's invalid because it's a twig file. Dangit testbot!

FYI I reported the testbot problem: #2663892: Testbot complaining that a twig file contains invalid PHP?

That's reasonable for now.

A shorter version of the patch in #17.

Thanks for spotting those, mr.baileys! Committed.

Committed. Thanks again.