Thumbnail files not being generated in 3.0

[jeryj]

After upgrading to 3.0, the "Keep WordPress Thumbnails" option no longer works. I've looked around at how to fix it, and I have a fix, but I'm not sure if my fix breaks another option, so I didn't want to put in a PR.

Basically, $this->keepThumbnails is used in in DynamicImagesTool->setup() before it's set by ImgixTool->setup().

The flow goes like:

DynamicImagesTool {
  setup() {
    if (!$this->keepThumbnails) {
            add_filter('wp_image_editors', function($editors) {
                array_unshift($editors, '\ILAB\MediaCloud\Tools\DynamicImages\DynamicImageEditor');

                return $editors;
            });
        }
   }
}

ImgixTool extends DynamicImagesTool {
   setup() {
      parent::setup();
     
       // keepThumbnails option is set _after_ the parent::setup(), so it's never set correctly to be used in parent::setup();
      $this->keepThumbnails = Environment::Option('mcloud-imgix-generate-thumbnails', null, true);
  }
}

So, the two fixes are:

1. In ImgixTool(), Move $this->keepThumbnails = Environment::Option('mcloud-imgix-generate-thumbnails', null, true); above parent::setup(); Or
2. Move the if (!$this->keepThumbnails) { ... } code from DynamicImagesTool()->setup() to after $this->keepThumbnails is set in ImgixTool()->setup().

I wasn't sure if one was better/worse than the other since I don't know the ins and outs of the plugin as well as you :) If it's easier for you, I'm happy to put in the PR for the best change if you let me know which one to go with (or some other one).