Adopt ni-python-styleguide for hand-written code

[bkeryan]

• This contribution adheres to CONTRIBUTING.md.
• I've updated CHANGELOG.md if applicable.
• I've added tests applicable for this pull request

What does this Pull Request accomplish?

Enable ni-python-styleguide for src/handwritten.

Fix about 600/800 style errors and use nps acknowledge-existing-violations --aggressive to add noqas for the remaining ~200.

Why should this Pull Request be merged?

I am sick of reviewing new code with style guide violations.

Closes #556

What testing has been done?

Ran poetry run nps lint

[bkeryan]

@zhindes To review this, you're probably better off looking at individual commits. Also, let's rebase this rather than squash it.

[bkeryan]

FYI @mikeprosserni This may cause some merge conflicts, but hopefully you're done with the big refactors.

[github-actions]

Test Results

    38 files  ±0      38 suites  ±0   1h 2m 10s ⏱️ -23s
 2 709 tests ±0   2 236 ✅ ±0    473 💤 ±0  0 ❌ ±0 
47 680 runs  ±0  40 210 ✅ ±0  7 470 💤 ±0  0 ❌ ±0 

Results for commit 674e797. ± Comparison against base commit b07a8d1.

[zhindes]

@zhindes To review this, you're probably better off looking at individual commits. Also, let's rebase this rather than squash it.

Yep that was very easy, thanks!