rss: Extract bbcode module

[TrimmingFool]

#2569 (review)

Could we possibly make a new class for parsing bbcode to html and transforming it?

@stickz I extracted the bbcode logic into a module. (I think, a module is simpler than a new class, here.)

[stickz]

Thanks, I will merge and test this in the new year. This will make the RSS plugin more robust in the long run.

[fabricionaweb]

This seems to broke the frontend rss test

 FAIL  plugins/rss/init.spec.js
  ● rss details › should sanitize html code

    TypeError: stub.getrssdetailsResponse is not a function

I tried to fix but to be honest I couldnt understand well what fails

[stickz]

Hello, @fabricionaweb the testing code is a low priority for the ruTorrent project. We implemented it as a precautionary measure to test some of our more complex changes.

If you'd like to contribute to the ruTorrent project, we have quite a few outstanding tasks in the issues report section. Just ping @stickz and I'll help out the best I can. Everything has been clearly labeled for easy understanding and resolution.