Fix Plugins Assets in FroalaHelper.php

[w-mazed]

I noticed that the helper loaded all the assets of the froala plugins without taking in consideration the array of plugins passed at the call function (editor function), that's why I changed the helper to load only the assets of the mentionned plugins.

So, I made two major edit at the helper .\src\View\Helper\FroalaHelper.php:

1. I used two arrays ($js_files and $css_files) to load the assets of each plugins, I put conditions to check if the plugin is required or not to load it assets.
2. I call the plugin function on the editor function (CakePHP doesn't load same files two times).

Sorry for my bad english.

• Best regards.