Fix formatting when requires have metadata

[camsaul]

Fixes #351

While working on this I tried to think of all the possible weird edge cases I could and found that it also broke in a few even weirder situations e.g. if you did something like put metadata on or comments before the x in [x :as y] itself. I added a pretty comprehensive test makes sure things work as expected no matter what shenanigans you're up to in your ns form.