Make buildProduction work with static sites with multiple html files

The first commit makes the population query include relations to local html-files.

The second commit is a refactoring of the old logic, that was inside the `moveAssetsInOrder`-transform, out to the query object it gets as an argument. By not including files that we know aren't being renamed we avoid a lot of cyclic dependency issues when doing graph traversals. Even simple webpages with two html-pages linking to each other are cyclic, which made it break right out of the box before.