Aggressive removal of other plugins' template tags

[ice9js]

Hello there!

I noticed that this plugin is quite aggressive in how it removes template tags from HTML content - in addition of processing its own tags it's also stripping any others that might be used by different plugins causing them not to work.
For example, in case of the Modula gallery plugin it'll cause the navigation not to render effectively making the view stuck.

With the tags not following any namespaces, it's a bit of a grey area although I'd say it should be fine to just leave those that aren't part of nimble builder as they are.

Steps to reproduce

• Install the Modula gallery plugin which uses {{arrows}} and {{buttons}} tags and create a gallery with 'arrow navigation' enabled.
• When viewing the page, you should notice empty .modula-fancybox-toolbar and .modula-fancybox-navigation elements. That's where the tags would go and their absence causes the plugins' JS not to inject the content.

Possible solution

Change ccat-constants-and-helper-functions.php#L2112 from:

return null;

to

return matches[0];