Improve no-dupe-disjunctions by reordering alternatives

[RunDevelopment]

To implement sort-alternatives, I had to implement a method to decide whether two alternatives can be reordered.

We can use this method to improve the reporting of no-dupe-disjunctions. Right now, superset alternatives are not reported by default (e.g. /\b(?:Foo|\w+)\b/). But if the alternatives can be reordered, a superset alternative can be become a subset alternative (e.g. /\b(?:Foo|\w+)\b/ == /\b(?:\w+|Foo)\b/).