PLAT-364 Add getCategoryByName back to WikiFactoryHub

This adds the getCategoryByName method back to WikiFactoryHub. There are some existing calls to this method that have not been removed so we need to continue to support this interface.

/cc @Wikia/platform-team @owend @inez 
Yeah, I was adding new/old params to most of these helpers as an aid for transition.  I plan to remove or refactor the helpers entirely and then the extra params can go away.