[#398] Reduce compilation time

Description

Improve compilation time of some modules in morley and lorentz - those were the most crucial.

There a couple of modules in indigo which take slightly long, but I'm not sure how to properly fix those, they already seem to be written well.

Related issue(s)

Resolves #398 (closed)

✅ Checklist for your Merge Request

Related changes (conditional)

• Tests (see short guidelines)

  • [x] If I added new functionality, I added tests covering it. I didn't manage to find a way to test individual modules compilation time.
  • If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

• Documentation

  • I checked whether I should update the docs and did so if necessary:
    • Root README and other README.md files
    • Haddock
    • docs/
  • I updated changelog files of all affected packages released to Hackage if my changes are externally visible.

Stylistic guide (mandatory)

• My commits comply with the following policy.
• My code complies with the style guide.