Fix CommonAPI.follow/2 return values order

While working on tests for !4205 (merged) I was baffled at why it didn't appear to be working only to discover that when I did the CommonAPI consistency refactoring in !4189 (merged) I didn't ensure the order of values returned from follow/2 matched the order they were provided to the function.

Very confusing.

This fixes it.

In the process of fixing the tests etc I've discovered some other functions that also have unintuitive ordering such as MastodonAPI.follow/2 and some functions in User and UserRelationship, but those are butterflies to chase another day...