Do not raise Utilityfunction for methods defined in a class_method block

[mateusluizfb]

Addresses https://github.com/troessner/reek/issues/1538

This PR implements a way to not raise UtilityFunction warning for methods defined in class_methods block

[troessner]

I am kind of hesitant to merge something that is specific to Rails but since it's seemingly used a lot...idk. Wdyt @mvz ?

[mvz]

Yes, I'm also wondering how we can support this in a more generic way. Also, I think there's in issue that the proposed solution will suppress UtilityFunction in the whole module instead of just inside the class_method block. I need to look into this a little bit more over the weekend.

[mvz]

To generalize this, we could add a configuration option to list which methods introduce a block that defines class methods. The default option would be empty, but users can set it to [:class_methods] if Reek is used in a Rails project.

[troessner]

Excellent idea @mvz!

[mateusluizfb]

@mvz nice idea, is there something in the project that I could reuse or base myself? Like a custom Rails configuration module or a class that does something similar

[troessner]

@mvz seems like we forgot this one, I can see that you assigned this to yourself, any chance you pick it up again?

[mateusluizfb]

Feel free to ping me again as well