Add RESUtils.isPageType('x', 'y') and 'modqueue' pageType

Based on #1856 
Therefore, fixes #1855 

Intended to simplify this repetition: `RESUtils.pageType() === 'x' || RESUtils.pageType() === 'y'...`. There are a few other fixes/refactoring thrown in as well.

Unfortunately, adding the modqueue page type requires replacing pretty much every single `'linklist'` test with `'linklist', 'modqueue'`. However, it does allow us to standardize a few `include:` regexes, and it makes sense (at least somewhat) because modqueue is more like a combination of `comments` and `linklist`.

Although this is a pretty drastic change so it may not be worth doing at all.