Ormolu pass + hlint + consistency tweaks

This is a large MR with a bunch of changes made by Ormolu + hlint.

I also made some small changes of my own, and applied Ormolu again on top of that:

• Removed explicit imports. Some dependencies added more than 20 lines of individual imports, and Ormolu only allows all in the same line or all in their own line.
• Added some newlines here and there to help Ormolu refactor definitions more inline.

The code is far from perfect, and many places can still benefit from some easy refactorings, but I'd argue we should apply them on demand, or we might end up refactoring code that gets rewritten anyways.